A law student, who want to check a professor's claim that convicted embezzlers spend on average 12.3 months in jail, takes a random sample of 36 such cases from court files. Using his results, namely, a mean of 10.8 months and a standard deviation of 3.9 months, test the hypothesis u=12.3 versus the alternative hypothesis u≠12.3 at a level of significance of 5% and at a level of significance of 1%.