Sanitation inspection of cruise ships. Refer to the Centers for Disease Control and Prevention study of sanitation levels for 169 international cruise ships, Exercise 1.23 (p. 18). (Recall that sanitation scores range from 0 to 100.) (a) Find y and s for the 169 sanitation scores. (b) Calculate the interval y 2s. (c) Find the percentage of scores in the data set that fall within the interval, part b. Does the result agree with the rule of thumb given in this section?