9- A track coach found out that distance runners from go aver their recommended mile run training limit by an average 7.6 miles with a standard deviation of 2.8 miles. You conduct a survey of 25 runners. You want to know the probability that the average runner ran more than 8.2 miles or P(Xbar > 8.2)

JA researcher takes an SRS of 80 people who go golfing.The average to be u52 years old. It was also determined that the standard deviation of cac ot golfers was la What is the probability that the sample mean is kss. than 47 years old? age of all golferswas determined years.

Cody took his first physics exam and scored an 80. The population mean for this exam is 70, and the standard deviation is 5. What is the probability of selecting a person with a score greater than Cody’s?

A business school dean in Ohio wants to know if graduates who completed an internship during their undergraduate years earn more than business undergraduates who do not complete an internship while in college.  Based on national survey from 1,500 business alumni with less than six years of work experience, they earn on average $50,970 with a standard deviation of $12,976.  Business alumni from the Ohio  school who completed internships on average earned $53,497.  The dean wants you to be 96% confident in your results. a. State in statistical terms the null and alternative hypotheses. b. Determine the appropriate test statistic (z or t). c. Determine the critical value(s). d. Compute the test statistic. e. Make a decision on the hypotheses. (which hypothesis is correct?) f. Determine the p-value for the test statistic.

A racing car consumes a mean of 106106 gallons of gas per race with a standard deviation of 66 gallons. If 3333 racing cars are randomly selected, what is the probability that the sample mean would be greater than 103.7103.7 gallons? Round your answer to four decimal places.