On a standard measure of hearing ability, the mean is 480 and the standard deviation is 20. Give the Z scores for persons who score (a) 540, (b) 500, and (c) 420. Give the raw scores for persons whose Z scores on this test are (d) 2.3, (e). 1.6, (f) 0, and (9) - 4.8. (a) The Z score is (Round to two decimal places as needed.)