A manufacturer of running shoes knows that the average lifetime
for a particular model of shoes is 15 months. A designer came with
a new model of shoes which were worn by 15 individuals, and the
lifetime of each of those pairs of shoes are given below:
15, 18, 17, 20, 16, 16.5, 15.5, 17.5, 19, 14, 21, 18.5, 16.5,
15, 14
a) State the appropriate hypotheses to test whether the lifetime
of shoes are showing evidence of a longer lasting product than
expected.
b) Determine the mean and standard deviation for the lifetimes
of the sample of shoes.
c) Test the hypotheses stated in part (a) at a 5% level of
significance, and comment on your findings.