1. A study was carried out to assess the effect of alcohol on pilots. Ten pilots performed a series of routinetasks at a simulated altitude of 25, 000 feet. Each pilot performed the tasks in a completely sobercondition and then three days later the pilot repeated the tasks after drinking alcohol. The responsevariable is the time (in seconds) of appropriate performance of the tasks. Bigger times are better. Thenull hypothesis is that alcohol has no effect, and the alternative is that performance degrades afteralcohol use. The data are provided below along with summaries.

a) Explain the experimental design and state the reasons to use this design. b) Carry out the appropriate t test. c) Obtain a 95% confidence interval for the difference in mean performance under the two-conditions. What do you conclude about the hypothesis based on your confidence interval?