1: Free testosterone levels were measured in 2 groups of men. Group 1 was composed of 15 men who currently smoked regularly. The mean score for this group was 285 pmol/L with a sample standard deviation of 44 pmol/L. The second group l, consisting of 12 men who had previously smoked and quit, had an average score of 248 pmol/L with a sample standard deviation of 36 pmol/L. Assuming normally distributed population: A: what is the 80% confidence interval for finding the difference between the two populations means? B: at this level, are the 2 population mean significantly different