Question

The cost of 5 gallons of ice cream has a variance of 49 with a mean of 31 dollars during the summer. What is the probability that the sample mean would be less than 32.3 dollars if a sample of 31 5-gallon pails is randomly selected? Round your answer to four decimal places. (show work)

Answer 1

Solution :

Given that ,

mean = = 31

standard deviation = = 7

= / n = 7 / 31 = 1.2572

P( < 32.3) = P(( - ) / < (32.3 - 31) / 1.2572)   

P(z < 1.0340)

= 0.8494

Probability = 0.8494