a company claims that the standard deviation in their delivery time is less than 5 days a sample of 27 past customers is taken the average delivery

a company claims that the standard deviation in their delivery time is less than 5 days a sample of 27 past customers is taken the average delivery time in the sample was 14 days withna standard deviation of 4.5 days at 95 confidence interval test the company claim use the cricical value approach