Statistics and Distributions

Homework Assignment from the Required Reading

Ch. 3: Complete #’s 2, 6, 12, and 14 (End of the Chapter)

2. What is meant by the statement, “The sample mean is an unbiased estimate of the population mean?”

The expectation of the sample mean is always the underlying population mean, no matter what the sample size.

6. In a distribution of scores, the median was 60, the mean was 98, and the mode was 42. What is the shape of the distribution?

12. Decide which measure of central tendency should be used in the following situations:

a. It is the only measure of central tendency that can be used for data measured on a nominal scale.

b. It can only be used for data measured on interval and ratio scales.

c. It can be used for all scales of measurement except nominal.

d. It should be used for distributions that are positively skewed.

e. It should be used for distributions that are negatively skewed.

f. It should be used for normally shaped distributions.

14. Given the following set of scores: 8, 10, 10, 7, 12, 10, 8, 10, 7, 9

a. what is the mode?

b. what is the median?

c. what is the mean?

Ch. 4: Complete #’s 2, 6, and 10 (End of the Chapter)

2. Why is the range sometimes problematic as a measure of variability?

6. Mathematically, how are the variance and standard deviation related?

10. Calculate the range for the following scores: 2.5, 6.8, 3.4, 4.4, and 5.6. (Hint: you may need to revisit the topic of real limits from chapter1.)