Question

1. A sample has a mean of M =90 and a standard deviation of s = 20 .
   1. Find the z-score for each of the following X values.

X = 95 X = 98 X = 105

X = 80 X = 88 X = 76

2. Find the X value for each of the following z-scores.

z = -1.00 z = 0.50 z = -1.50

z = 0.75 z = -1.25 z = 2.60

Answer 1

With the mean of M =90 and a standard deviation of s = 20, the Z score is calculated as:

a) At X = 95

At X = 98

at X = 105

at X = 80

at X =88

at X = 76

b) With similar formula the X can be calculated at given Z scores a:

at Z =-1.00

at Z =0.50

at Z = -1.50

at Z = 0.75

at Z = -1.25

at Z = 2.60