Question 45469
A study of 100 QDA professors showed that the time to create a test question was 13.0 minutes. The standard deviation of the population was 2. Find the 90% confidence interval of the population mean.

Margin of error = 1.645(2/sqrt100)=0.329
Confidence interval = (13-0.329,13+0.329)
=(12.671,13.329)

Cheers,
Stan H.