A survey was conducted to determine the number of hours people listen to the radio. While most of the listening is in the car, it turns out that the mean is 2.5 hours with a standard deviation of 0.75 hours. Find the probability that the sum of 80 values is greater than 190.

Question

A survey was conducted to determine the number of hours people listen to the radio. While most of the listening is in the car, it turns out that the mean is 2.5 hours with a standard deviation of 0.75 hours. Find the probability that the sum of 80 values is greater than 190.

Answer 1

190 what? Minutes? Hours?

Z = (score-mean)/SEm

SEm = SD/√n

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability related to the Z score.