CDF

Given a Z value, CDF command calculates the area under the normal distribution curve to the left of the specified z(Z<=z). If m and standard deviation s are not specified, a standard normal distribution( s=1, m=o), is assumed. If X has the N(m,s) distribution, then the standardized variable z=(X-m)/s has the standard normal distribution N(0,1) .
The proportion of soldiers have head circumference greater than 23.9 inches( Section 1.3 Exercises 1.62 in BPS page 64) can be found by selecting Calc--> Probability Distributions-->Normal and filling in the dialog as shown.

The result is stored in constant k1, which can be viewed by opening Info window. However, k1 is the proportion of soldiers have head circumference less and equal to 23.9 inches, which is not appropriate result we want. What we really want is the proportion of soldiers have head circumference greater than 23.9 inches, which is "1-k1". Use command LET to get it.

MTB>let k2=1-k1

Then we can view k1 and k2 in Info window, which shown as below.

Or by using command PRINT to read any data or constant in session window.

MTB>print k1 k2

Session window shows as below.


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