An apple orchard would like to estimate the average weight of their apples to be within 0.2 ounces with 95% confidence. A small random sample of 50 apples indicates a sample mean weight of 10.2 ounces with a sample standard deviation of 2.5. if we can assume the weights of the apples are normally distributed, how many apples need to be measured to ensure that the margin of error will be 0.2 ounces.