Compute the z-score corresponding to each of the following values of x:

a. x = 40, s = 5, x = 30

b. x = 90, m = 89, s = 2

c. m = 50, s = 5, x = 50

d. s = 4, x = 20, x = 30

e. In parts a–d, state whether the z-score locates x within a sample or within a population.

f. In parts a–d, state whether each value of x lies above or below the mean and by how many standard deviations.