HP 20B

Mathematical Calculations
26
2. Type the number for which you want to calculate the probability, or, for the inverse, the probability for which
you want the number.
3. Navigate to the appropriate function in the Probability sub-menu of the Math menu.
Table 2-6 Probability Example
Keys Display Description
10I
8I
:s
Enters 10 degrees of freedom and the number for which
probability is to be calculated. Opens the Math menu.
<<I
<<<<
Selects the Probability menu item and scrolls to Chi
2
.
I or =
Validates the result.
Table 2-7 Inverse Probability Example
Keys Display Description
10I
0.37
12I
:s
Enters 10 degrees of freedom and the probability. Opens
the Math menu.
<<I
<<<<
<
Selects the Probability menu item. Scrolls to Chi
2-1
.
I or =
Validates the result.
Two-Number Functions
Apart from +-*/, the three additional two-number functions accessible on the keyboard are:
 Y
x