Question

I

n general, high school and college students are the most pathologically sleep-deprived segment of the population. Their alertness during the day is on par with that of untreated narcoleptics and those with untreated sleep apnea. Not surprisingly, teens are also 71 percent more likely to drive drowsy and/or fall asleep at the wheel compared to other age groups. (Males under the age of twenty-six are particularly at risk.)

The accompanying data set represents the number of hours 25 college students at a small college in the northeastern United States slept and is from a random sample. Enter this data into C1 of Minitab Express.

6 9 7 7 6 7 7 5 8 6 6 6 8 8 8 5 4 6 7 8 5 8 7 6 7

For the analyses that follow, we shall use

·         90%, 95%, and 99% as the confidence levels for the confidence interval.

·      5% as the level of significance ( ) for the hypothesis test.

·         7 hours sleep as the null hypothesis (according to The Sleep Foundation).

a.    Minitab Express (STATISTICS, Distribution Plot, Display Probability, Choose “t” under the Distribution list, Choose Equal Tails, enter the probability left in both tails—10%, 5% and 1%) to determine the t critical values for 90%, 95%, and 99% confidence intervals about a population mean .

b.    Write the equation that you will use for computing the bounds (limits) for a confidence interval about a population mean.

Answer 1