The state test scores for 12 randomly selected high school seniors are shown on the right. Complete parts (a) through (c) below. Assume the population is normally distributed. 1424 690 724 625 1221 724 740 1446 982 835 547 940 (a) Find the sample mean. x= 90B2 (Round to one decimal place as needed.) (b) Find the sample standard deviation s= (Round to one decimal place as needed.)