Consider the following set of sample data:

Question

(34, 32, 34, 32, 40, 37, 31, 31, 29, 27)

We're interested in using this data to test a null hypothesis about the population mean. Which of the following statements are true?

1. Assuming this represents a random sample from the population, the

sample mean is an unbiased estimator of the population mean. II. We'd use t-procedures here if the population does not contain outliers or extreme skewness.

III. We'd use z-procedures here, since we're interested in the population mean.

A. I only

B. II only

OC. III only

D. I and II only

E. I and III only

Answer 1

A. I only

Statement I is true because the sample mean is an unbiased estimator of the population mean. Statement II is not necessarily true because we would still use t-procedures even if the population does not contain outliers or extreme skewness. Statement III is not true because we would use t-procedures, not z-procedures, when testing hypotheses about the population mean with a small sample size.