PSYC 354 Quiz 4

PSYC 354 Quiz 4: Standard Deviation and z-Scores

1. Which z-score corresponds to a score that is above the mean by 2 standard deviations?
2. One purpose of a z-score is to provide an understanding of the exact location of a score in a distribution.
3. Which z-score value represents the location farthest from the mean?
4. Transforming an entire distribution of scores into z-scores changes an originally positively skewed distribution to a negatively skewed z-score distribution.
5. Transforming a set of scores into a standardized distribution of z-scores consists of graphically _____ the scores.
6. For any distribution, what is the z-score corresponding to the mean?
7. A positive z-score always corresponds to a score that is greater than the mean in a distribution.
8. Which position in a distribution corresponds to a z-score of z = –1.00?
9. Consider a population that has a score of X = 15 associated with a z-score of +1.50. What does this z-score indicate about the location of X = 15?
10. For a population with μ = 40 and σ = 8, what is the z-score corresponding to X = 34?
11. 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 σ = 12.
12. For a population with a mean of μ = 60 and a standard deviation of σ = 4, a score of X = 56 corresponds to a z-score of z
    = –0.50.
13. For a sample with s = 9, a score of X = 67 corresponds to z = +1.00. What is the sample mean?
14. For a sample with M = 50 and s = 12, what is the X value corresponding to z = –0.25?
15. A population has μ = 50. Which value of σ would make X
    = 55 an extreme value out in the tail of the population distribution?