The mean pulse rate and standard deviation of a random sample of 9 first years male medical Students were 68.7 and 8.67 beats per minute respectively. (Assume normal distribution).

a) Find a 95% C.I. for the population mean.

b) If past experience indicates that the mean pulse rate of first year male medical students is 72 beats per minute, test the hypothesis that the above sample estimate is consistent with the population mean at 5% level of significance.