Question: "Driving impairment due to sleepiness is exacerbated by low alcohol intake." Table 1 on the top of page 691 presents mean blood alcohol concentrations (BAC) and standard errors of the mean (SE in Table 1) for the participants before driving. The values are given for the "With sleep restriction" and "No sleep restriction" conditions.

a. Compute 95% confidence intervals for the mean BAC before driving for each of the two conditions. (Note that the sample sizes are smaller than may be appropriate for using the method in this chapter, but that will cause the intervals to be just slightly too narrow, or alternatively, the confidence to be slightly less than 95%. You can ignore that detail.)

b. Interpret the interval for the "With sleep restriction" condition. Make sure your explanation refers to the correct population.

c. Ignoring the fact that the sample size is slightly too small, would it be appropriate to compute a confidence interval for the difference in the two means using the method provided in this chapter? If so, compute the interval. If not, explain why not. You may have to read the article to determine whether the appropriate condition is met.