6.46 Distributions and life expectancy: Researchers have reported that the projected life expectancy for South African men diagnosed with human immunodeficiency virus (HIV) at age 20 who receive antiretroviral therapy (ART) is 27.6 years (Johnson et al., 2013). Imagine that the researchers determined this by following 250 people with HIV who were receiving ART and calculating the mean.

a. What is the dependent variable of interest?

b. What is the population?

c. What is the sample?

d. For the population, describe what the distribution of scores would be.

e. For the population, describe what the distribution of means would be.

f. If the distribution of the population were skewed, would the distribution of scores likely be skewed or approximately normal? Explain your answer.

g. Would the distribution of means be skewed or approximately normal? Explain your answer.