A random sample of 400 incomes of unionized transit workers was taken in order to estimate the mean household income and the percentage of incomes that exceed $80,000. The results of this random sample yields the following results: a. Sample Mean = $40,000. b. Sample Standard Deviation = $7,500 C. The number of incomes that exceed $80,000 is 60. A 95% confidence interval for the percentage of incomes that exceed $80,000 in the population of all transit workers is: O (13.8, 16.2) C) (11.5, 18.5) 0 (10.6, 19.4) C) (12.7 , 18.3) C) (9.3 , 20.7)