Answer to Question #59275 in Statistics and Probability for asma

Question

1) A survey was conducted to measure the number of hours per week adults spend on home computers. In the survey, the number of hours were normally distributed, with a mean of 7 hours and a standard deviation of 1.5 hours.

a) What is the probability that the sample mean of 9 participants exceeds 8 hours?

b) What is the probability that the sample mean of 9 participants is below 6.5 hours?


c) What is the probability that the sample mean of 25 participants is between 6.8 and 7.8 hours?