For a distribution
_ _
X = 100 and s=4. If x= X then z=?
If x = 90, then z =?
If z=2, then x=?
If z=1.5, then x =?
If X is the mean value, then z = 0 when x = X
x = 90, you are 2.5s below the mean, so z = -2.5
If x = 2, you are 8 above the mean, so x = 108
If z = 1.5, you are 6 above the mean, so x = 106