PSYC 354 Quiz 3 Variability

PSYC 354 Quiz 3: Variability

1. For a sample with M = 10 and s = 2, a score of X = 13 would be considered an extreme score, far out in the tail of the distribution.
2. Data sets can be divided into four quartiles.
3. If sample variance were to be computed by dividing SS by n, then the average value of the sample variances from all the possible random samples would consistently _____ the population variance.
4. For a population of scores, the sum of the deviation scores is equal to 0.
5. Which set of scores below has the smallest standard deviation?
6. Which of the following is a consequence of increasing variability?
7. It is only appropriate and possible to calculate the variance and standard deviation as measures of variability for variables measured using a(n) _____ scale of measurement.
8. A researcher conducts a research study to examine how a new treatment for anxiety compares in efficacy to a standard therapy. This researcher assigns clinically anxious participants to either a new treatment or standard treatment for six months, and then observes anxiety levels following. The researcher finds that the new treatment group has an average anxiety score of M = 50 with a standard deviation of s = 5 following treatment, whereas the standard treatment group has an average anxiety score of M = 60 with a standard deviation of s = 6. Which statement below is consistent with how these results would be reported in an APA style journal article?
9. The box plot below depicts the median number of hours a population of N = 12 students reported studying for their first exam within a class. Which statement below is not true based on the box plot?
10. What the variance for the following sample of n = 3 scores? Scores: 1, 4, 7
11. What is the variance for the following population of scores? Scores: 2, 5, 6, 3
12. What is the range for the following set of scores obtained for a discrete variable for which 0 is not a possible score? Scores: 5, 7, 9, 13
13. A sample of n = 9 scores has SS = 72. The variance for this sample is s2 = 9.
14. If the population variance is 6, then the population standard deviation is σ = 36.
15. What is the value of SS (sum of squared deviations) for the following sample? Scores: 2, 4, 5, 9