A researcher believes that women today weigh less than in previous years. To investigate this belief, he randomly samples 41 adult women and records their weights. The scores have a mean of 111 lb & and a standard deviation of 12.4. A local census taken several years ago shows the mean weight of adult women was 115 lbs.(a) The obtained value of the appropriate statistic for testing H0 is.(b) The dl for determined t is.(c) Using α=0.01 the appropriate critical value.