Seventy million pounds of trout are grown in the U.S. every year. Farm-raised trout contain an average of32 grams of fat per pound, with a standard deviation of7 grams of fat per pound. A random sample of40 farm-raised trout is selected. The mean fat content for the sample is31.5 grams per pound. Find the probability of observing a sample mean of31.5 grams of fat per pound or less in a random sample of40 farm-raised trout.

Carry your intermediate computations to at least four decimal places. Round your answer to at least three decimal places.