From extensive records, it is known that the duration of treating a
disease by a standard therapy has a mean of 15 days. It is claimed that a new
therapy can reduce the treatment time. To test this claim, the new therapy is
tried on 70 patients, and from the data of their times to recovery, the sample
mean and standard deviation are found to be 14.6 and 3.0 days, respectively.
(a) Calculate the P-value and interpret the result.
(b) Would you reject your null hypothesis at 2.5% level of significance?