What price do farmers get for their watermelon crops? In the third week of July, a random sample of40farming regions gave a sample mean of= $6.88per 100 pounds of watermelon. Assume thatis known to be$1.98per 100 pounds.

Find the sample size necessary for a 90% confidence level with maximal error of estimateE=0.45for the mean price per 100 pounds of watermelon. (Enter a number. Round up to the nearest whole number.)