48. More than 50 million guests stay at bed and breakfasts (B&Bs) each year. The website for the Bed and Breakfast Inns of North America, which averages seven visitors per minute, enables many B&Bs to attract guests (Time, September 2001).

a. Compute the probability of no website visitors in a one-minute period.

b. Compute the probability of two or more website visitors in a one-minute period.

c. Compute the probability of one or more website visitors in a 30-second period.

d. Compute the probability of five or more website visitors in a one-minute period.

20. The average price for a gallon of gasoline in the United States is $3.73 and in Russia it is $3.40 (Bloomberg Businessweek, March 5-March 11, 2012). Assume these averages are the population means in the two countries and that the probability distributions are normally distributed with a standard deviation of $.25 in the United States and a standard deviation of $.20 in Russia.

a. What is the probability that a randomly selected gas station in the United States charges less than $3.50 per gallon?

b. What percentage of the gas stations in Russia charge less than $3.50 per gallon?

c. What is the probability that a randomly selected gas station in Russia charged more than the mean price in the United States?

23. The time needed to complete final examination in a particular college course is normally distributed with a mean of 80 minutes and a standard deviation of 10 minutes. Answer the following questions.

a. What is the probability of completing the exam in one hour or less?

b. What is the probability that a student will complete the exam in more than 60 minutes but less than 75 minutes?

c. Assume that the class has 60 students and that the examination period is 90 minutes in length. How many students do you expect will be unable to complete the exam in the allotted time?

16. The data from exercise 2 follow. 3 12 6 20 14 vi 55 40 55 10 15 The estimated regression equation for these data is j = 68 - 3x. a. Compute SSE, SST, and SSR. b. Compute the coefficient of determination r2. Comment on the goodness of fit. c. Compute the sample correlation coefficient.18. The following data show the brand, price ($), and the overall score for six stereo headphones that were tested by Consumer Reports (Consumer Reports website, March 5, 2012). The overall score is based on sound quality and effectiveness of ambient noise reduction. Scores range from 0 (lowest) to 100 (highest). The estimated regression equation for these data is = 23.194 + .318x, where x = price ($) and y = overall score.Brand Price Score Bose 180 76 Skullcandy 150 71 Koss 95 61 Phillips/O'Neill 70 56 Denon 70 40 JVC 35 26 a. Compute SST, SSR, and SSE. b. Compute the coefficient of determination r2. Comment on the goodness of fit. c. What is the value of the sample correlation coefficient