# Understanding Statistics In the Behavioral Sciences 9th Edition by Robert R. Pagano – Test Bank

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Understanding Statistics In the Behavioral Sciences 9th Edition by Robert R. Pagano – Test Bank

Sample  Questions

Chapter 5—The Normal Curve and Standard Scores

MULTIPLE CHOICE

Exhibit 5-1

A stockbroker has kept a daily record of the value of a particular stock over the years and finds that prices of the stock form a normal distribution with a mean of \$8.52 with a standard deviation of \$2.38.

1. Refer to Exhibit 5-1. The percentile rank of a price of \$13.87 is ____.
 a. 48.78% b. 1.22% c. 98.78% d. 51.22%

ANS:  C                    PTS:   1

1. Refer to Exhibit 5-1. What percentage of the distribution lies between \$5 and \$11?
 a. 21.48% b. 78.41% c. 49.41% d. 57.98%

ANS:  B                    PTS:   1

1. Refer to Exhibit 5-1. What percentage of the distribution lies below \$7.42?
 a. 17.72% b. 32.28% c. 82.28% d. 31.92%

ANS:  B                    PTS:   1

1. Refer to Exhibit 5-1. The stock price beyond which 0.05 of the distribution falls is ____.
 a. \$  4.60 b. \$12.47 c. \$  4.57 d. \$12.44

ANS:  D                    PTS:   1

1. Refer to Exhibit 5-1. The percentage of scores that lie between \$9.00 and \$10.00 is ____.
 a. 15.31% b. 31.17% c. 23.24% d. 7.93%

ANS:  A                    PTS:   1

Exhibit 5-2

A testing bureau reports that the mean for the population of Graduate Record Exam (GRE) scores is 500 with a standard deviation of 90. The scores are normally distributed.

1. Refer to Exhibit 5-2. The percentile rank of a score of 667 is ____.
 a. 3.14% b. 96.78% c. 3.22% d. 96.86%

ANS:  D                    PTS:   1

1. Refer to Exhibit 5-2. The proportion of scores that lie above 650 is ____.
 a. 0.4535 b. 0.9535 c. 0.0475 d. 0.0485

ANS:  C                    PTS:   1

1. Refer to Exhibit 5-2. The proportion of scores that lie between 460 and 600 is ____.
 a. 0.4394 b. 0.5365 c. 0.4406 d. 0.4635

ANS:  B                    PTS:   1

1. Refer to Exhibit 5-2. The raw score that lies at the 90th percentile is ____.
 a. 615.2 b. 384.8 c. 616.1 d. 383.9

ANS:  A                    PTS:   1

1. Refer to Exhibit 5-2. The proportion of scores between 300 and 400 is ____.
 a. 0.3665 b. 0.4868 c. 0.8533 d. 0.1203

ANS:  D                    PTS:   1

1. The standard deviation of the z distribution equals ____.
 a. 1 b. 0 c. S X d. N

ANS:  A                    PTS:   1

1. The mean of the z distribution equals ____.
 a. 1 b. 0 c. S X d. N

ANS:  B                    PTS:   1

1. The z score corresponding to the mean of a raw score distribution equals ____.
 a. the mean of the raw scores b. 0 c. 1 d. N

ANS:  B                    PTS:   1

1. The normal curve is ____.
 a. linear b. rectangular c. bell-shaped d. skewed

ANS:  C                    PTS:   1

1. In a normal curve, the inflection points occur at ____.
 a. m ± 1s b. ±1s c. m ± 2s d. m

ANS:  A                    PTS:   1

1. The z score corresponding to a raw score of 120 is ____.
 a. 1.2 b. 2.0 c. 1.0 d. impossible to compute from the information given

ANS:  D                    PTS:   1

Exhibit 5-3

An economics test was given and the following sample scores were recorded:

 Individual A B C D E F G H I J Score 12 12 7 10 9 12 13 8 9 8

1. Refer to Exhibit 5-3. The mean of the distribution is ____.
 a. 12 b. 10 c. 9 d. 8

ANS:  B                    PTS:   1

1. Refer to Exhibit 5-3. The standard deviation of the distribution is ____.
 a. 10.2 b. 2.1 c. 2.11 d. 10.74

ANS:  C                    PTS:   1

1. Refer to Exhibit 5-3. The z score for individual D is ____.
 a. 1 b. 0 c. 10 d.

ANS:  B                    PTS:   1

1. Refer to Exhibit 5-3. The z score for individual E is ____.
 a. 0.47 b. 9 c. 4.27 d. -0.47

ANS:  D                    PTS:   1

1. Refer to Exhibit 5-3. The z score for individual G is ____.
 a. -1.42 b. 13 c. 1.42 d. 6.16

ANS:  C                    PTS:   1

Exhibit 5-4

A distribution has a mean of 60.0 and a standard deviation of 4.3.

1. Refer to Exhibit 5-4. The raw score corresponding to a z score of 0.00 is ____.
 a. 64.3 b. 14 c. 4.3 d. 60

ANS:  D                    PTS:   1

1. Refer to Exhibit 5-4. The raw score corresponding to a z score of -1.51 is ____.
 a. 53.5 b. 66.5 c. 66.4 d. 53.6

ANS:  A                    PTS:   1

1. Refer to Exhibit 5-4. The raw score corresponding to a z score of 2.02 is ____.
 a. 51.3 b. 68.7 c. 51.4 d. 68.6

ANS:  B                    PTS:   1

1. If a population of scores is normally distributed, has a mean of 45 and a standard deviation of 6, the most extreme 5% of the scores lie beyond the score(s) of ____.
 a. 35.13 b. 45.99 c. 56.76 and 33.24 d. 45.99 and 35.13

ANS:  C                    PTS:   1

1. If a distribution of raw scores is negatively skewed, transforming the raw scores into z scores will result in a ____ distribution.
 a. normal b. bell-shaped c. positively skewed d. negatively skewed

ANS:  D                    PTS:   1                    MSC:  WWW

1. The mean of the z distribution equals ____.
 a. 0 b. 1 c. N d. depends on the raw scores

ANS:  A                    PTS:   1                    MSC:  WWW

1. The standard deviation of the z distribution equals ____.
 a. 0 b. 1 c. the variance of the z distribution d. b and c

ANS:  D                    PTS:   1

1. S(zmz) equals ____.
 a. 0 b. 1 c. the variance d. cannot be determined

ANS:  A                    PTS:   1

1. The proportion of scores less than z = 0.00 is ____.
 a. 0 b. 0.5 c. 1 d. -0.5

ANS:  B                    PTS:   1

1. In a normal distribution the z score for the mean equals ____.
 a. 0 b. the z score for the median c. the z score for the mode d. all of the above

ANS:  D                    PTS:   1                    MSC:  WWW

1. In a normal distribution approximately ____ of the scores will fall within 1 standard deviation of the mean.
 a. 14% b. 95% c. 70% d. 83%

ANS:  C                    PTS:   1

1. Would you rather have an income (assume a normal distribution and you are greedy) ____?
 a. with a z score of 1.96 b. in the 95th percentile c. with a z score of -2.00 d. with a z score of 0.000

ANS:  A                    PTS:   1                    MSC:  WWW

1. How much would your income be if its z score value was 2.58?
 a. \$10,000 b. \$  9,999 c. \$  5,000 d. cannot be determined from information given

ANS:  D                    PTS:   1

1. Which of the following z scores represent(s) the most extreme value in a distribution of scores assuming they are normally distributed?
 a. 1.96 b. 0.0001 c. -0.0002 d. -3.12

ANS:  D                    PTS:   1                    MSC:  WWW

1. Assuming the z scores are normally distributed, what is the percentile rank of a z score of -0.47?
 a. 31.92 b. 18.08 c. 50 d. 47 e. 0.06

ANS:  A                    PTS:   1                    MSC:  WWW

1. A standardized test has a mean of 88 and a standard deviation of 12. What is the score at the 90th percentile? Assume a normal distribution.
 a. 90 b. 112 c. 103.36 d. 91

ANS:  C                    PTS:   1                    MSC:  WWW

1. On a test with a population mean of 75 and standard deviation equal to 16, if the scores are normally distributed, what is the percentile rank of a score of 56?
 a. 58.3 b. 0 c. 25.27 d. 38.3 e. 11.7

ANS:  E                    PTS:   1                    MSC:  WWW

1. On a test with a population mean of 75 and standard deviation equal to 16, if the scores are normally distributed, what percentage of scores fall below a score of 83.8?
 a. 55 b. 79.12 c. 20.88 d. 29.12 e. 70.88

ANS:  E                    PTS:   1                    MSC:  WWW

1. On a test with a population mean of 75 and standard deviation equal to 16, if the scores are normally distributed, what percentage of scores fall between 70 and 80?
 a. 75.66 b. 70 23 c. 24.34 d. 23.57 e. 12.17

ANS:  C                    PTS:   1                    MSC:  WWW

1. You have just received your psychology exam grade and you did better than the mean of the exam scores. If so, the z transformed value of your grade must
 a. be greater than 1.00 b. be greater than 0.00 c. have a percentile rank greater than 50% d. can’t determine with information given e. b and c.

ANS:  E                    PTS:   1

1. You have just taken a standardized skills test designed to help you make a career choice. Your math skills score was 63 and your writing skills score was 45. The standardized math distribution is normally distributed, with m = 50, and s = 8. The writing skills score distribution is also normally distributed, with m = 30, and s = 10. Based on this information, as between pursuing a career that requires good math skills or one requiring good writing skills, you should chose
 a. neither, your skills are below average in both b. the career requiring good math skills. c. neither, this approach is bogus; dream interpretation should be used instead. d. the career requiring good writing skills.

ANS:  D                    PTS:   1

1. A distribution of raw scores is positively skewed. You want to transform it so that it is normally distributed. Your friend, who fancies herself a statistics whiz, advises you to transform the raw scores to z scores; that the z scores will be normally distributed. You should
 a. Ignore the advice because your friend flunked her last statistics test b. Ignore the advice because z distributions have the same shape as the raw scores. c. Take the advice because z distributions are always normally distributed d. Take the advice because z distributions are usually normally distributed

ANS:  B                    PTS:   1

1. All bell-shaped curves
 a. are normal curves b. have means = 0 c. are symmetrical d. a and c

ANS:  C                    PTS:   1

1. If you transformed a set of raw scores, and then added 15 to each z score, the resulting scores
 a. would have a standard deviation = 1 b. would have a mean = 0 c. would have a mean =15 d. would have a standard deviation > 1 e. a and c

ANS:  E                    PTS:   1

1. A set of raw scores has a rectangular shape. The z transformed scores for this set of raw scores has a ____ shape.
 a. rectangular b. normal (bell-shaped) c. it depends on the number of scores in the distribution d. none of the above

ANS:  A                    PTS:   1

1. Makaela took a Spanish exam; her grade was 79. The distribution was normally shaped with  = 70 and s = 12. Juan took a History exam; his grade was 86. The distribution was normally shaped with  = 80 and s = 8. Which did better on their exam relative to those taking the exam?
 a. Makaela. b. Juan. c. Neither, they both did as well as each other. d. Makaela, because her exam was harder e. a and d.

ANS:  C                    PTS:   1

1. Table A (Areas under the normal curve) in your textbook has no negative z values, this means ____.
 a. the table can only be used with positive z values b. the table can be used with both positive and negative z values because it is symmetrical c. the table can be used with both positive and negative z values because it is skewed d. none of the above

ANS:  B                    PTS:   1

1. A testing service has 1000 raw scores. It wants to transform the distribution so that the mean = 10 and the standard deviation = 1. To do so, ____.
 a. Do a z transformation for each raw score and add 10 to each z score. b. Do a z transformation for each raw score and multiply each by 10 c. Divide the raw scores by 10 d. Compute the deviation score for each raw score. Divide each deviation score by the standard deviation of the raw scores. Take this result for all scores and add 10 to each one. e. a and d

ANS:  E                    PTS:   1

1. Given the following set of sample raw scores, X: 1, 3, 4, 6, 8. What is the z transformed value for the raw score of 3?
 a. -0.18 b. -0.48 c. -0.15 d. -0.52

ANS:  D                    PTS:   1

TRUE/FALSE

1. A z distribution always is normally shaped.

ANS:  F                    PTS:   1

1. All standard scores are z scores.

ANS:  T                    PTS:   1

1. A z score is a transformed score.

ANS:  T                    PTS:   1

1. A z score designates how many standard deviations the raw score is above or below the mean.

ANS:  T                    PTS:   1                    MSC:  WWW

1. The z distribution takes on the same shape as the raw scores.

ANS:  T                    PTS:   1                    MSC:  WWW

1. z scores allow comparison of variables that are measured on different scales.

ANS:  T                    PTS:   1

1. In a normal curve, the area contained between the mean and a score that is 2.30 standard deviations above the mean is 0.4893 of the total area.

ANS:  T                    PTS:   1

1. The normal curve reaches the horizontal axis in 4 standard deviations above and below the mean.

ANS:  F                    PTS:   1

1. For any z distribution of normally distributed scores, P50 is always equal to zero.

ANS:  T                    PTS:   1                    MSC:  WWW

1. If the original raw score distribution has a mean that is not equal to zero, the mean of the z transformed scores will not equal zero either.

ANS:  F                    PTS:   1

1. It is impossible to have a z score of 30.2.

ANS:  F                    PTS:   1                    MSC:  WWW

1. The area under the normal curve represents the proportion of scores that are contained in the area.

ANS:  T                    PTS:   1                    MSC:  WWW

1. If the raw score distribution is very positively skewed, the standard deviation of the z transformed scores will not equal 1.

ANS:  F                    PTS:   1

1. The area beyond a z score of -1.12 is the same as the area beyond a z score of 1.12.

ANS:  T                    PTS:   1

1. A raw score that is 1 standard deviation above the mean of the raw score distribution will have a z score of 1.

ANS:  T                    PTS:   1

DEFINITIONS

1. Define asymptotic.

ANS:

PTS:   1                    MSC:  WWW

1. Define normal curve.

ANS:

PTS:   1

1. Define standard (z) scores.

ANS:

PTS:   1                    MSC:  WWW

1. List three characteristics of a z distribution.

ANS:

PTS:   1                    MSC:  WWW

1. Is a z distribution always normally shaped? Explain.

ANS:

PTS:   1

1. Does the z transformation result in a score having the same units of measurement as the raw score? Explain. Why is this advantageous?

ANS:

PTS:   1                    MSC:  WWW

1. Are all bell-shaped curves normal curves? Explain.

ANS:

PTS:   1

1. What is meant by a transformed score? Give an example.

ANS:

PTS:   1

1. If a score is at the mean of a set of raw scores, where will it be if the set of raw scores is transformed to z scores? Why?

ANS:

PTS:   1

Chapter 7—Linear Regression

MULTIPLE CHOICE

1. The primary reason we use a scatter plot in linear regression is ____.
 a. to determine if the relationship is linear or curvilinear b. to determine the direction of the relationship c. to compute the magnitude of the relationship d. to determine the slope of the least squares regression line

ANS:  A                    PTS:   1

1. When the relation between X and Y is imperfect, the prediction of Y given X is ____.
 a. perfect b. always equal to Y c. impossible to determine d. approximate

ANS:  D                    PTS:   1

1. The regression equation most often used in psychology minimizes ____.
 a. S (Y – Y’) b. S (Y – Y’)2 c. S (Y – X)2 d. e. none of the above

ANS:  B                    PTS:   1

1. The regression of Y on X ____.
 a. predicts X given Y b. predicts X’ given X c. predicts Y given X d. predicts Y given Y’

ANS:  C                    PTS:   1

1. The regression of X on Y ____.
 a. predicts Y given X b. predicts Y given X c. predicts X given Y d. is generally the same as the regression of Y on X e. c and d

ANS:  C                    PTS:   1

1. If the correlation between two sets of scores is 0 and one had to predict the value of Y for any given value of X, the best prediction of Y would be ____.
 a. bY b. c. 0 d.

ANS:  B                    PTS:   1

1. During the past 5 years there has been an inflationary trend. Listed below is the average cost of a gallon of milk for each year.

 1981 1982 1983 1984 1985 \$1.10 \$1.23 \$1.30 \$1.50 \$1.65

Assuming a linear relationship exists, and that the relationship continues unchanged through 1986, what would you predict for the average cost of a gallon of milk in 1986?

 a. \$1.77 b. \$1.72 c. \$1.70 d. \$1.83

ANS:  A                    PTS:   1

Exhibit 7-1

A researcher collects data on the relationship between the amount of daily exercise an individual gets and the percent body fat of the individual. The following scores are recorded.

 Individual 1 2 3 4 5 Exercise (min) 10 18 26 33 44 % Fat 30 25 18 17 14

1. Refer to Exhibit 7-1. Assuming a linear relationship holds, the least squares regression line for predicting % fat from the amount of exercise an individual gets is ____.
 a. Y’ =   0.476X + 33.272 b. Y’ =   1.931X + 66.363 c. Y’ = -0.476X + 33.272 d. Y’ = -0.432X + 32.856

ANS:  C                    PTS:   1

1. Refer to Exhibit 7-1. If an individual exercises 20 minutes daily, his predicted % body fat would be ____.
 a. 21.63 b. 27.74 c. 27.88 d. 23.75

ANS:  D                    PTS:   1

1. Refer to Exhibit 7-1. The least squares regression line for predicting the amount of exercise from % fat is ____.
 a. X’ = -1.931Y + 66.363 b. X’ = -0.476Y + 33.272 c. X’ =   1.931Y + 66.363 d. X’ = -1.905Y + 62.325

ANS:  A                    PTS:   1

1. Refer to Exhibit 7-1. If an individual has 22% fat, his predicted amount of daily exercise is ____.
 a. 22.8 b. 23.88 c. 24.76 d. 20.22

ANS:  B                    PTS:   1

1. Refer to Exhibit 7-1. The value for the standard error of estimate in predicting % fat from daily exercise is ____.
 a. 3.35 b. 4.32 c. 2.14 d. 1.66 e. none of the above

ANS:  C                    PTS:   1

1. The assumption of homoscedasticity is that ____.
 a. the range of the Y scores is the same as the X scores b. the X and Y distributions have the same mean values c. the variability of Y doesn’t change over the X scores d. the variability of the X and Y distributions is the same

ANS:  C                    PTS:   1

1. You go to a carnival and a sideshow performer wants to bet you \$100 that he can guess your exact weight just from knowing your height. It turns out that there is the following relationship between height and weight.

 Height (in) 60 62 63 66.5 73.5 84 Weight (lbs) 99 107 111 125 153 195

Should you accept the performer’s bet? Explain.

 a. yes b. need more information c. no d. yes, if he measures my height in centimeters

ANS:  C                    PTS:   1

1. If r = 0.4582, sY = 3.4383, and sX = 5.2165, the value of bY = ____.
 a. 0.695 b. 0.458 c. 0.302 d. 1 – 0.458 e. none of the above

ANS:  C                    PTS:   1

1. In multiple regression, if the second predictor variable correlates highly with the predicted variable, than it is quite likely that ____.
 a. R2 = 1.00 b. R2 > r2 c. R2 = r2 d. R2 < r2

ANS:  B                    PTS:   1

1. If the relationship between X and Y is perfect:
 a. r = b b. the equation for Y‘ equals the equation for X‘ c. prediction is approximate d. a and b e. all of the above

ANS:  D                    PTS:   1

1. When predicting Y, adding a second predictor variable to the first predictor variable X, will ____.
 a. always increase prediction accuracy b. increase prediction accuracy depending on the relationship between the second predictor variable and X c. Increase prediction accuracy depending on the relationship between the second predictor variable and Y d. b and c

ANS:  D                    PTS:   1

1. The higher the standard error of estimate is,
 a. the more accurate the prediction is likely to be b. the less accurate is the prediction is likely to be c. the less confidence we have in the accuracy of the prediction d. the more confidence we have in the accuracy of the prediction e. a and d f. b and c

ANS:  F                    PTS:   1

1. If sY|X = 0.0 the relationship between the variables is ____.
 a. perfect b. imperfect c. curvilinear d. unknown

ANS:  A                    PTS:   1                    MSC:  WWW

1. S (YY’) equals ____.
 a. 0 b. 1 c. cannot be determined from information given d. who cares

ANS:  A                    PTS:   1

1. S (YY’)2 represents ____.
 a. the standard deviation b. the variance c. the standard error of estimate d. the total error of prediction

ANS:  D                    PTS:   1                    MSC:  WWW

1. In a particular relationship N = 80. How many points would you expect on the average to find within ±1sY|X of the regression line?
 a. 40 b. 80 c. 54 d. 0

ANS:  C                    PTS:   1

1. What would you predict for the value of Y for the point where the value of X is ?
 a. cannot be determined from information given b. 0 c. 1 d.

ANS:  D                    PTS:   1

1. If the value of sY|X = 4.00 for relationship A and sY|X = 5.25 for relationship B, in which relationship would you have the most confidence in a particular prediction?
 a. A b. B c. it makes no difference d. cannot be determined from information given

ANS:  A                    PTS:   1                    MSC:  WWW

1. If bY is negative, higher values of X are associated with ____.
 a. lower values of X’ b. higher values of Y c. higher values of (Y – Y’) d. lower values of Y

ANS:  D                    PTS:   1

1. Which of the following statement(s) is (are) an important consideration(s) in applying linear regression techniques?
 a. the relationship should be linear b. both variables must be measured in the same units c. predictions for Y should be within the range of the X variable in the sample d. a and c

ANS:  D                    PTS:   1                    MSC:  WWW

1. In the regression equation Y’ = X, the Y-intercept is ____.
 a. b. c. 0 d. 1

ANS:  C                    PTS:   1

1. If the value for aY is negative, the relationship between X and Y is ____.
 a. positive b. negative c. inverse d. cannot be determined from information given

ANS:  D                    PTS:   1                    MSC:  WWW

1. If bY = 0, the regression line is ____.
 a. horizontal b. vertical c. undefined d. at a 45° angle to the X axis

ANS:  A                    PTS:   1

1. The least-squares regression line minimizes ____.
 a. s b. sY|X c. S (Y – )2 d. S (Y – Y’)2 e. b and d

ANS:  E                    PTS:   1

1. The points (0,5) and (5,10) fall on the regression line for a perfect positive linear relationship. What is the regression equation for this relationship?
 a. Y’ = X + 5 b. Y’ = 5X c. Y’ = 5X + 10 d. cannot be determined from information given.

ANS:  A                    PTS:   1

1. For the following points what would you predict to be the value of Y’ when X = 19? Assume a linear relationship.

 X 6 12 30 40 Y 10 14 20 27

 a. 16.35 b. 24.69 c. 22 d. 17.75

ANS:  A                    PTS:   1                    MSC:  WWW

1. If N = 8, S X = 160, S X2 = 4656, S Y = 79, S Y2 = 1309, and S XY = 2430, what is the value of bY?
 a. 0.9217 b. -1.801 c. 0.5838 d. 0.7922

ANS:  C                    PTS:   1

1. If X and Y are transformed into z scores, and the slope of the regression line of the z scores is -0.80, what is the value of the correlation coefficient?
 a. -0.8 b. 0.8 c. 0.4 d. -0.4

ANS:  A                    PTS:   1                    MSC:  WWW

1. If the regression equation for a set of data is Y’ = 2.650X + 11.250 then the value of Y’ for X = 33 is ____.
 a. 87.45 b. 371.25 c. 98.7 d. 76.2

ANS:  C                    PTS:   1                    MSC:  WWW

1. If  = 57.2,  = 84.6, and bY = 0.37, the value of aY = ____.
 a. 141.8 b. -25.9 c. 63.44 d. 27.4

ANS:  C                    PTS:   1

1. If the regression line for predicting X given Y were X’ = 103Y + 26.2, what would the value of X’ be if Y = 0.2?
 a. 129.2 b. 25.8 c. 5.2 d. 46.8

ANS:  D                    PTS:   1

1. If sY = sX = 1 and the value of bY = 0.6, what will the value of r be?
 a. 0.36 b. 0.6 c. 1 d. 0

ANS:  B                    PTS:   1

1. When using more than one predictor variable, ____ tells us the proportion of variance accounted for by the predictor variables.
 a. r b. SSX c. SSY d. R2

ANS:  D                    PTS:   1                    MSC:  WWW

1. Which of the following statements is(are) false?
 a. bY is the slope of the line for minimizing errors in predicting Y. b. aY is the Y axis intercept for minimizing errors in predicting Y. c. sY½X is the standard error of estimate for predicting Y given X. d. All of the above statements are true. e. R2 is the multiple coefficient of nondetermination.

ANS:  E                    PTS:   1                    MSC:  WWW

1. The regression coefficient bY and the correlation coefficient r ____.
 a. necessarily increase in magnitude as the strength of relationship increases b. are both slopes of straight lines c. are not related d. will equal each other when the variability of the X and Y distributions are equal e. b and d

ANS:  E                    PTS:   1

1. When predicting Y given X, ____.
 a. the prediction is valid only within the range of X b. the variability of the Y values over the range of the X values should be the same c. the representativeness of the sample used to derive the regression line is an important consideration d. a, b, and c e. a and c

ANS:  D                    PTS:   1

1. When predicting Y from two variables relative to using only one variable, ____.
 a. prediction accuracy always increases b. prediction accuracy is dependent on the relationship between the second variable and the Y variable c. increase in prediction accuracy depends on the correlation between the two predictor variables d. b and c

ANS:  D                    PTS:   1

1. There is ____ between the sY|X and r.
 a. a direct relationship b. an inverse relationship c. no relationship d. animosity

ANS:  B                    PTS:   1

1. The regression coefficient for predicting Y given X is symbolized by ____
 a. bY b. aY c. bX d. aX

ANS:  A                    PTS:   1

1. The regression coefficient for predicting X given Y is symbolized by ____.
 a. bY b. aY c. bX d. aX

ANS:  C                    PTS:   1

1. The regression constant for predicting Y given X is symbolized by ____.
 a. bY b. aY c. bX d. aX

ANS:  B                    PTS:   1

1. The regression constant for predicting X given Y is symbolized by ____.
 a. bY b. aY c. bX d. aX

ANS:  D                    PTS:   1

1. The symbol for the standard error of estimate when predicting Y given X is ____.
 a. rX|Y b. sX|Y c. rY|X d. sY|X

ANS:  D                    PTS:   1

TRUE/FALSE

1. The total error in prediction equals S (YY’).

ANS:  F                    PTS:   1                    MSC:  WWW

1. In general, the regression line for predicting X given Y is the same as the regression line for predicting Y given X.

ANS:  F                    PTS:   1

1. An imperfect relationship generally yields exact prediction.

ANS:  F                    PTS:   1

1. When the relationship is perfect, the regression of Y on X is the same as the regression of X on Y.

ANS:  T                    PTS:   1                    MSC:  WWW

1. Properly speaking, we should limit our predictions to the range of the base data.

ANS:  T                    PTS:   1

1. The least squares regression line insures the maximum number of direct hits.

ANS:  F                    PTS:   1                    MSC:  WWW

1. To do linear regression, there must be paired scores on two variables.

ANS:  T                    PTS:   1

1. If the standard deviations of the X and Y distributions are equal, then r = bY.

ANS:  T                    PTS:   1

1. If sX = sY then bX = bY.

ANS:  T                    PTS:   1                    MSC:  WWW

1. The higher the r value, the lower the standard error of estimate.

ANS:  T                    PTS:   1                    MSC:  WWW

1. Multiple regression uses more than one predictor variable.

ANS:  T                    PTS:   1

1. Multiple regression always results in greater prediction accuracy than simple regression.

ANS:  F                    PTS:   1

1. If the correlation between two variables is 1.00, the standard error of estimate equals 0.

ANS:  T                    PTS:   1

1. Pearson r is the slope of the least squares regression line when the scores are plotted as z scores.

ANS:  T                    PTS:   1

1. When there are two predictor variables, R2 is the simple sum of r2 for the relationship of the first predictor variable and Y and r2 for the relationship of the second predictor variable and Y.

ANS:  F                    PTS:   1

DEFINITIONS

1. Define Homoscedasticity.

ANS:

PTS:   1

1. Define least-squares regression line.

ANS:

PTS:   1                    MSC:  WWW

1. Define multiple coefficient of determination.

ANS:

PTS:   1

1. Define multiple correlation.

ANS:

PTS:   1

1. Define regression.

ANS:

PTS:   1

1. Define regression constant.

ANS:

PTS:   1

1. Define regression line.

ANS:

PTS:   1

1. Define regression of X on Y.

ANS:

PTS:   1                    MSC:  WWW

1. Define regression of Y on X.

ANS:

PTS:   1

1. Define standard error of estimate.

ANS:

PTS:   1

1. Why is it important to know the standard error of estimate for a set of paired scores?

ANS:

PTS:   1

1. Why does the least squares regression line minimize S (YY’)2, rather than S (YY’)?

ANS:

PTS:   1                    MSC:  WWW

1. Is it true that, generally, the regression lines for predicting Y given X and X given Y, are not the same? Explain.

ANS:

PTS:   1

1. The least squares regression line is the prediction line that results in the most direct “hits.” Is this true? Explain.

ANS:

PTS:   1

1. In what situation would the regression line for predicting Y given X be the same as the line predicting X given Y? Explain.

ANS:

PTS:   1

1. In multiple regression, will use of a second predictor variable always increase the accuracy of prediction? Explain.

ANS:

PTS:   1                    MSC:  WWW

1. If there is no relationship between the X and Y variables and we desire to predict Y given X using a least-squares criterion, it is best to predict  for every Y score. Is this correct? If so, explain why. (Hint: one of the properties of the mean might be helpful here)

ANS:

PTS:   1                    MSC:  WWW

1. A friend that thinks a lot about statistics asserts that, “the closer the points in the scatter plot are to the least-squares regression line, the higher the correlation.” Is your friend correct? Discuss.

ANS: