Given a z-score, a standard normal table tells us the area between the mean and the desired z-score. We want to know the area between z = -1.5 and z = 1.2.
Since the standard distribution is symmetric, the area between the mean and z = - 1.5 is the same as the area between the mean and z = 1.5.
We need to check the areas for z = 1.2 and z = 1.5 in the standard table and sum them.
We have our values. Their sum is
The area between z = -1.5 and z = 1.2 is 0.8181.