Chapter 5

If two individuals in the same population have identical X scores, they also will have identical z-scores. T or F?

True

In a sample with s = 6, a score of X = 53 corresponds to z = -0.50. The mean for this sample is M = 56. T or F?

True

A score that is 6 points above the mean corresponds to a z-score of z = +0.50. For this population, the standard deviation is ao = 3. T or F?

False

A positive z-score always corresponds to a score that is greater than the mean. T or F?

True

A professor standardizes exam scores so that all exams have u = 50 and ao = 10. If the original scores from an exam have u = 42 and ao = 6, then a student with an original exam score of X = 45 would receive a standardized score of X = 55. T or F?

True

A z-score of z = +1.00 always indicates a location exactly 1 standard deviation above the mean. T or F?

True

For a population with a mean of u = 60 and a standard deviation of ao = 8, a score of X = 56 corresponds to z = -0.50. T or F?

True

For a population with a mean of u = 80, any score greater than 80 will have a positive z-score. T or F?

True

For a sample with a mean of M = 50 and a standard deviation of s = 10, a z-score of z = +2.00 corresponds to X = 70. T or F?

True

For any distribution of scores, the location identified by z = +1 and the location identified by z = -1 are exactly the same distance from the mean. T or F?

True

On an exam with ao = 6, Tom's scores of X = 54 corresponds to z = -1.00. The mean for the exam must be u = 60. T or F?

True

On an exam, Tom scored 12 points above the mean and had a z-score of +2.00. The standard deviation for the set of exam scores must be ao = 6. T or F?

True

For a population with u = 70 and ao = 8, what is the z-score corresponding to X = 82?

a) +0.25 b) +0.75 c) +1.25 d) +1.50*

What z - score corresponds to a score that is above the mean by 2 standard deviations?

a) +2* b) +10 c) +20 d) impossible to determine without knowing the value of the standard deviation

For a population with u = 40 and ao = 8, what is the z-score corresponding to X = 34?

a) -0.50 b) -0.75* c) -1.00 d) -1.50

For a population with u = 80 and ao = 6, what is the z-score corresponding to X = 68?

a) -0.50 b) -2.00* c) +2.00 d) -12.00

For any distribution, what is the z-score corresponding to the median?

a) 0 b) 1 c) N d) cannot be determined from the information given*

For any distribution, what is the z-score corresponding to the mean?

a) 0* b) 1 c) N d) cannot be determined from the information given

A population distribution has ao = 6. What position in this distribution is identified by a z=score of z = +2.00?

a) 2 points above the mean b) 2 points below the mean c) 12 points above the mean* d) 12 points below the mean

For a population with u = 80 and ao = 10, what is the X value corresponding to z = -2.00?

a) 78 b) 75 c) 70 d) 60*

For a population with u = 100 and ao = 20, what is the X value corresponding to z = -0.75?

a) 85* b) 95 c) 105 d) 115

For an exam with a mean of M = 74 and a standard deviation of s = 8, Mary has a score of X = 80, Bob's score corresponds to z = +1.50, and Sue's score is located above the mean by 10 points. If the students are placed in order from smallest score to largest score, what is the correct order?

a) Bob, Mary, Sue b) Sue, Bob, Mary c) Mary, Bob, Sue d) Mary, Sue, Bob*

Last week Tim got a score of X = 54 on a math exam with u = 60 and ao = 8. He also got X = 49 on an English exam with u = 55 and ao = 3, and he got X = 31 on a psychology exam with u = 37 and ao = 4. For which class should Tim expect the best grade?

a) Math* b) English c) Psychology d) All 3 grades should be the same

Last week, Sarah had exams in math and in Spanish. On the math exam, the mean was u = 30 with ao = 5, and Sarah had a score of X = 45. On the Spanish exam, the mean was u = 60 with ao = 8, and Sarah had a score of X = 68. For which class should Sara expect the better grade?

a) Math* b) Spanish c) the grades should be the same because the two exam scores are in the same location d) there is not enough information to determine which is the better grade

A sample has M = 72 and s = 4. In this sample, what is the X value corresponding to z = -2.00?

a) X = 70 b) X = 68 c) X = 64* d) X = 60

In N = 25 games last season, the college basketball team averaged u = 76 points with a standard deviation of ao = 6. In their final game of the season, the team scored 89 points. Based on this information, the number of points scored in the final game was __________.

a) a little above average b) far above average* c) above average, but it sim impossible to describe how much above average d) there is not enough information to compare last year with the average

On an exam with u = 52, you have a score of X = 44. Which value for the standard deviation would give you the highest position in the class distribution?

a) ao = 2 b) ao = 4 c) ao = 8* d) cannot determine from the information given

On an exam with u = 52, you have a score of X = 56. Which value for the standard deviation would give you the highest position in the class distribution?

a) ao = 2* b) ao = 4 c) ao = 8 d) cannot determine from the information given

What position in the distribution corresponds to a z - score of z = -1.00?

a) below the mean by 1 point b) below the mean by a distance equal to 1 standard deviation* c) above the mean by 1 point d) above the mean by a distance equal to 1 standard deviation

Under what circumstances is a score that is 15 points above the mean an extreme score relatively far from the mean?

a) when the population mean is much larger than 15 b) when the population mean is much greater than 5 c) when the population standard deviation is much less than 5 d) when the population standard deviation is much greater than 5*

Under what circumstances is a score that is located 5 points above the mean a central value, relatively close to the mean?

a) when the population mean is much less than 5 b) when the population mean is much greater than 5 c) when the population standard deviation is much less than 5 d) when the population standard deviation is much greater than 5*

Which of the following z - score values represents the location farthest from the mean?

a) z = +0.50 b) z = +1.00 c) z = -1.00 d) z = -2.00*

In a sample with M = 40 and s = 8, what is the z-score corresponding to X = 38?

a) z = -0.25* b) z = -0.50 c) z = 0.25 d) z = 0.50

For a population with a standard deviation of ao = 6, what is the z-score corresponding to a score that is 12 points above the mean?

a) z =1 b) z = 2* c) z = 6 d) z = 12