1. Quiz 2
Measures of central tendency
Measures of variability

2. a) arithmetic mean b) median c) mode d) midrange
1. Which measure of central tendency divides a sample into two parts of equal size (i.e., n/2)?
a) arithmetic mean
b) median
c) mode
d) midrange

3. 2.What is the coefficient of variation for a test with mean 25 and SD 10?
b) 10%
c) 25%
d) 2.5%

4. 3. Compute the z-score for a test score of 35 from a test that had a mean of 50 and SD of 10.
b) 3.5
c) -3.5
d) -1.5

5. 4. Given a z-score of 1.20 what was the test score on a test with mean of 40 and SD of 12?
b) 52.0
c) 54.4
d) 25.6

6. 5. In normally distributed data approximately ____% of scores lie within +/–1 SD of the mean?

7. 6. Which phrase best describes the following distribution?
a) negatively skewed
b) positively skewed
c) normally distributed

8. 7. What is the median of the following ordered list of numbers?
23, 45, 66, 67, 68, 80, 102
a) 64.4
b) 66.5
c) 67.0
d) 67.5

9. 8. Standard deviation is defined as the _________.
a) square root of the variance
b) square of the variance
c) mean divided by the variance
d) range divided by 2