The average age of online consumersten years ago was 23.3 years. As older individuals gain
confidence with the Internet, it isbelieved that the average age has increased. We would like totest
this belief.
(a) Write the appropriate hypothesesto be tested.
(b) The online shoppers in our sampleconsisted of 40 individuals, had an average age of 24.2
years, with a standard deviation of5.3 years. What is the test statistic and pâ€value for the
hypotheses being tested in part (a)?(Remark: Report the pâ€value using the statisticaltable,
but NOT Excelfunction.)
(c) What is the practicalimplication of the conclusion of the hypothesis test at
- Â Â Â Â Â Â Â 5% level ofsignificance, and
- Â Â Â Â Â Â Â 10% level ofsignificance?
(d) Is our current sample large enoughto estimate the mean age of online consumers to be
correct within ±1.5 years at 95% levelof confidence? If not, how many additional individuals
need to be selected?
