The authors of a paper describe an experiment to evaluate the effect of using a cellphone on reaction time. Subjects were asked to perform a simulated driving task while taking on a cell phone. While performing this task occasional red and green lights flashed on the computer screen. If a green light flashed subjects were to continue driving, but if a red light flashed, subjects were to brake as quickly as possible. The reaction time ( in msec ) was recorded. The following summary statistics are based on a graph that appeared in the paper.
n= 41 x= 525 s= 65
a. assuming that this sample is random/representative of the population, what other assumptions need to be true before we can create a confidence interval?
b. construct a 98% confidence interval for ?, the
c. draw a conclusion about the 98% confidence interval for ?, the mean time to react to a red light while talking on a cell phone
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