statistics
posted by Gregory .
On a standard measure of hearing ability, the mean is 300 and the standard deviation is 20. Give the Z scores for persons who score (a) 340, (b) 310, and (c) 260. Give the raw scores for persons whose Z scores on this test are (d) 2.4, (e) 1.5, (f) 0, and (g) –4.5.

z = (value  mean)/SD
I'll do one of each type. It requires only algebra once you have the equation.
a. z = (340  300)/20
z = 2
d. 2.4 = (value  300)/20
48 = value  300
value = 348