21 The average American man consumes 9.8 grams of sodium each day. Suppose that the sodium consumption of American men is normally.r distributed with a standard deviation of 0.9 grams. Suppose an American man is randomly chosen. Let X = the amount of sodium consumed. Round all numeric answers to 4 decimal places where possible. a. What is the distribution of X? )1 ~ Hi{ II 1 b. Find the probability that this American man consumes between 8.8 and 9.8 grams of sodium per day. c. The middle 1896- of American men consume between what two weights of sodium? Low: I I High: I I I 22 The mean height of an adult giraffe is 18 feet. Suppose that the distribution is normally distributed with standard deviation 0.9 feet. Let K be the height of a randomlyr selected adult giraffe. Round all answers II 4 decimal places where possible. a. what is the distribution of it? it ~ Ni| || 1. b. What is the median giraffe height? | |it. c. 1Ii'il'hat is the l-score for a giraffe that is 19.5 foot tall?| d. What is the probability that a randomly.r selected giraffe will be shorter than 1?.2 feet tall? e. What is the probability that a randomly.r selected giraffe will be between 1?.1 and 13".? feet tall? f. The Tth percentile for the height of giraffes is ft. 23 B on Suppose that the distance of y balls hit to the outfieLd {in basebaLl] is normally distributed with a mean of 259 feet and a standard deviation of 44 feet. Let X be the distance in feet for a fly ball. a. What is the distribution of X? DIE ~ N{ ,l J b. Find the probability that a randomly hit fly ball travels less than 221 feet. Round to 4 decimal places. c. Find the 85th percentile for the distribution of distance of fly balls. Round to 2 decimal places. ' 'feet 24 Em: pts '0: The average student loan debt for college graduates is $25,950. Suppose that that distribution is normal and that the standard deviation is $13,550. Let X = the student loan debt of a randomly selected college graduate. Round all probabilities to 4 decimal places and all dollar answers to the nearest dollar. a. What is the distribution of X? X ' N{ b Find the probability that the college graduate has between $17,100 and $34,400 in student loan debt. c. The middle 1033 of college graduates' loan debt lies between what two numbers? Low: SI i High: 5|. i 25 On the planet of Mercury, 4-year-olds average 2.9 hours a day unsupervised. Most of the unsupervised children live in rural areas, considered safe. Suppose that the standard deviation is 1.5 hours and the amount of time spent alone is normally distributed. We randomly survey one Mercurian 4-year-old living in a rural area. We are interested in the amount of time X the child spends alone per day. (Source: San Jose Mercury News) Round all answers to 4 decimal places where possible. a. What is the distribution of X? X ~ N( b. Find the probability that the child spends less than 2.3 hours per day unsupervised. c. What percent of the children spend over 2 hours per day unsupervised. (Round to 2 decimal places) d. 81% of all children spend at least how many hours per day unsupervised? hours