What are the three strategic steps you can take to minimize the margin of error of a confidence interval around a
population mean?
The data below represent X = Therapy Hours Per Year, that a typical NFL Football player spends with their therapist.
Construct a 95 percent two-tailed confidence interval on the population mean, MU, from the sample data set in the
table. (You must calculate some preliminary measures from the data and then construct the confidence interval.)
Populate the Yellow Cells with the correct values, calculate the necessary values you need to use and then use that
information to create and interpret your confidence interval.
Therapy Hours per Year
X
F
FX
F(XX)
28
4
57
8
69
7
72
13
80
20
85
16
90
12
160
5
How large of a sample size do I need to be 90 percent confident that my margin of error, MoE, will be no more than
2.0 points, when the known population standard deviation, sigma, is equal to 19 points? Please show all the
necessary steps to arrive at the answer and also provide a reasonable interpretation. Show your work.
