A survey of 25 randomly selected customers found the ages shown (in years). The mean is 31.92 years and the standard deviation is 9.70 years. a) How many degrees of freedom does the t-statistic have? b) How many degrees of freedom would the tstatistic have if the sample size had been 100? 46 22 39 38 48 44 33 44 33 34 31 17 21 25 43 36 24 44 33 20 21% 30 1 5 3O 27