Posted by alessandria on .
A business researcher wants to estimate the average number of years of experience an account manager has working with the company before getting promoted to account manager. Eight account managers are randomly selected and asked how long they worked with the company before becoming an account manager. The resulting answers were: 1.2, 4.0, 3.6, 0.7, 5.8, 3.3, 2.8, 4.1
Use Excel and these data to compute a 90% confidence interval to estimate the average length of time an account manager spent working for the company before they were promoted to account manager. Print out your answer.

statistics 
MathGuru,
Formula for confidence interval:
CI90 = mean ± 1.645(sd/√n)
You will have to determine the mean and standard deviation. Sample size = 8
Using the formula by hand will double check your calculations.