Question 1159716: A corporation that maintains a large fleet of company cars for the use of its sales staff is interested in the mean distance driven monthly per sales person. The following table gives the monthly distances in miles driven by a random sample of 11 sales persons:
2365, 2319, 1861, 2528, 2007, 2266, 2663, 2687, 2135, 1979, 2056
Based on this sample, find a 95% confidence interval for the mean number of miles driven monthly by members of the sales staff, assuming that monthly driving distances are normally distributed.
Carry your intermediate computations to at least three decimal places. Round your answers to one decimal place. (If necessary, consult a list of formulas.)
What is the lower limit of the confidence interval?
What is the upper limit of the confidence interval?
Answer by Boreal(15235)   (Show Source):
You can put this solution on YOUR website! The mean is 2260.545
s=281.161
the half-interval is t (0.975, df=10)*s/sqrt(n)
t is 2.228
the half-interval is 2.23*281.16/sqrt(11)
=188.87
add and subtract that from the mean
(2071.7, 2449.4) is the 95% CI of the mean.
|
|
|
