Question

1. Suppose X is normal with ?=10 and ?=5. Find x0 such that P(X?x0)=0.0643 10.8 15 10.32 17.6 2.4

2. A survey was conducted to measure the number of hours per week adults in the United States spend on home computers. In the survey, the number of hours was normally distributed, with a mean of 7 hours and a standard deviation of 1 hour. A survey participant is randomly selected. Which of the following statements is true?

The probability that the hours spent on the home computer by the participant are between 4.5 and 9.5 hours per week is 0.0124.

If 43 adults in the United States are randomly selected, you would expect to say about 1 adult spend less than 5 hours per week on a home computer.

The probability that the hours spent on the home computer by the participant are less than 4.5 hours per week is 0.9938.

0.13% of the adults spend more than 4 hours per week on a home computer.

The probability that the hours spent on the home computer by the participant are more than 9.5 hours per week is 0.9938. 3. The length of gestation for swine is normally distributed with mean 114 days and standard deviation 0.75 day. Find the probability that a litter will be born within one day of the mean of 114, i.e., P(113<X<115). 0.9032 0.0918 0.9082 0.8164 none of the above 4. Heights X of adult women are normally distributed with mean 63.7 inches and standard deviation 2.71 inches. Romeo, who is 69.25 inches tall, wishes to day only women who are shorter than he but within 4 inches of his height, i.e., P(65.25<X<69.25). Find the probability that the next woman he meets will have such a height. 0.5 0.0694 0.9306 none of the above 0.2634

5. Weights of newborn babies in a certain state have normal distribution with mean 5.33 lb and standard deviation 0.65 lb. A newborn weighing less than 4.85 lb is considered to be at-risk, that is, has a higher mortality rate.

(a) A baby just born in this state is picked at random. The probability that the baby is at-risk is about                            [ Select ]                       ["0.23", "0.53", "0.43", "0.33", "0.13"]      

(b) The hospital wants to take pictures of the heaviest 10% of the newborn babies. The minimum weight (in lbs) required for a picture to be taken is about                           [ Select ]                       ["6.16", "7.27", "8.12", "5.89", "9.12"]      

Answer 1