Calculating Poisson Probabilities - Casio fx-9860GII Instructions Manual

b When using the lower bound probability to calculate other probabilities,
it is easier to do this without the wizard.
MENU
Press . Choose 1: RUN·MAT and press
P(5 ≤ X ≤ 15) = P(X ≤ 15) – P(X ≤ 4)
Press STAT |
OPTN F5
menu.
Enter binominalCD(15, 20, 0.45) – binominalCD(4, 20, 0.45)
P(5 ≤ X ≤ 15) = 0.980 (to 3 sf )
c P(X > 11) = 1 – P(X ≤ 11)
Enter 1 – binominalCD (11, 20, 0.45)
P (X > 11) = 0.131 (to 3 sf )

Calculating Poisson probabilities

5.13 Calculating Poisson probabilities
Example 55
X is a discrete random variable and X ~ Po (0.5)
Calculate i P(X = 2)
P(X ≤ 2)
ii
P(X > 2)
iii
×
−
0 5 .
e ( . ) 0 5
= =
i P X ( 2 )
2 !
The calculator can fi nd this value directly.
Press MENU and choose 2: STAT and press
F5
F6
Press DIST |
probability density function.
Enter the X value and the parameter.
Leave Data as Variable and Save Res as None.
Select Execute and press
© Oxford University Press 2012: this may be reproduced for class use solely for the purchaser's institute
DIST | BINM to enter the binomial
F3 F5
2
EXE .
| F1 POISN| F1 Ppd to use the Poisson
EXE .
EXE
.
Casio fx-9860GII
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Continued on next page
Using a graphic display calculator 49