Data Set 20

$3.04

$7.07

$2.82

$3.03

$3.28

$4.91

$4.09

$5.49

$5.02

$4.15

$4.53

$3.06

$5.56

$6.08

$2.87

$4.56

$5.20

$2.48

$4.12

$3.55

$3.49

$6.24

$5.01

$2.43

$4.70

$2.31

$7.41

$7.09

$4.81

$6.62

From the data set of fuel prices above;

Find the mean and standard deviation for the data set. Please do not try to do this by hand, but use the functions in Excel.

Find the Confidence Interval for your data.

Sample initial post:

• First find the mean and standard deviation.
• Then put this in an excel cell=confidence.norm(0.5,stdev,samplesize)and hit enter. This is the E value. (Note: please use your standard deviation and sample size and not the words.)
• Set up your confidence interval: (mean-E, mean+E)

Formula you used above for the confidence interval:

The formula is E= zsubc * sigma / sqrt n

Where the left hand endpoint is xbar - E and the right hand endpoint is xbar + E