Question

The cost of 55 gallons of ice cream has a standard deviation of 8 dollars with a mean of 29 dollars during the summer.

What is the probability that the sample mean would be greater than  27.1 dollars if a sample of 92 5-gallon pails is randomly selected? Round your answer to four decimal places.

Answer 1

Solution :

Given that ,

mean = = 29

standard deviation = = 8

= / n = 8 / 92 = 0.8341

P( > 27.1) = 1 - P( < 27.1)

= 1 - P[( - ) / < (27.1 - 29) / 0.8341]

= 1 - P(z < -2.2779)

= 1 - 0.0114

= 0.9886

Probability = 0.9886