A simple random sample of eight college freshmen were asked how many hours of sleep they typically got per night. The results were

Notice that one joker said that he sleeps 24 hours a day.

a. The data contain an outlier that is clearly a mistake.
Eliminate the outlier, then construct a 95% confidence interval for the mean amount of sleep from the remaining values.

b. Leave the outlier in and construct the 95%
confidence interval. Are the results noticeably different? Explain why it is important to check data for outliers.

Transcribed Image Text:

7.5 8.0 6.5 24 8.5 6.5 7.0 7.5