this is the link for my question httptinypiccomr33zblua8Solu

this is the link for my question

http://tinypic.com/r/33zblua/8

Solution

Set up null and alternate hypotheses as:

H0: mu = 12.6\'

Ha: mu not equal to 12.6\'

Two tailed test

Alpha = 0.01

Sample mean = 9.1 ft

Mean difference = -8.9

std dev = 0.7

Std error = 0.7/rt 18 = 0.1650

t statistic = -8.9/0.1650 = -5.243

p value =0.00006

As p < alpha reject null hypothesis

Mean has changed considerably.