In grading apples into "A," "B", and "C", an orchard uses weights to distinguish apples. Any apple weighing more than 2 ounces is classified as Grade "A", while an apple weighing less than 0.75 ounces is classified as Grade "C". If the day's pick shows 16.6% are Grade "A" and 6.68% are Grade "C", determine the mean and the standard deviation (assume weights are normally distributed).

We are to calculate the z values for the probabilities given and then set up the equations to solve for the mean and the standard deviation but I'm lost...I have been calculating z values so far using the mean and the standard deviation and just cannot solve this problem.

Not wanting answers...just hoping someone will be able to make this a little clearer for me. Thanks very much...Shannon