User`s guide
Statistical Calculations134
Example 2
The variable Z is a standard normal random variable. What is the probability that z is greater
than 1.2 or less than -1.2?
Figure 18
The desired area is to the right of 1.2 and to the left of -1.2. Since normal distributions are
symmetrical, and the areas are the same, you can calculate the lower tail area and simply
multiply by 2.
Table 12-24 Example converting from lower tail
Keys Display Description
J7Gy]F
.115070 Calculate the lower tail area and
store the value.
PG4
.230139 Calculates the result.










