The average length of time customers spent on waiting at ABCStore’s check-out counter before a new P.O.S. system was installedwas 4.3 minutes. A sample of 40 customers randomly selected at thecheck-out counter after the new P.O.S. system was installed showedthat the average waiting time was 3.5 minutes with a samplestandard deviation of 2.8 minutes. We wish to determine if theaverage waiting time after the P.O.S. system was installed is lessthan 4.3 minutes.
1.   State the null and alternative hypotheses tobe tested. (2 Points)
2.   Compute the test statistic. (2Points)
3.   Determine the critical value for this testat the 0.05 level of significance. (2 Points)
4.   What do you conclude at the 0.05 level ofsignificance? (2 Points)
5.   Construct a 95% confidence interval for theaverage waiting time after the new P.O.S. system was installed.
