Evaluating probability functions with calculator TI-83plus.doc
May 7’09
Computing factorials, permutations, and combinations with TI-83plus calculator
// see the file
Perm_Comb_and_Probability_Distributions.doc
* To compute
n!
,
enter the whole number
n
in your calculator, then press the
[MATH]
key, select
PRB
with the
right
arrow key
, then select
4: !
with the
down
arrow key ▼,
and press the
[ENTER]
key
twice
.
* To compute the number of
permutations
,
n
P
r
,
enter the whole number
n
in your
calculator, then press the
[MATH]
key, select
PRB
with the
right
arrow key
, then
select
2:
n
P
r
with the
down
arrow key ▼, and press the
[ENTER]
key. Then enter the
whole number
r
and press the
[ENTER]
key.
* To compute the number of
combinations
,
n
C
r
,
enter the whole number
n
in your
calculator, then press the
[MATH]
key, select
PRB
with the
right
arrow key
, then
select
3:
n
C
r
with the
down
arrow key ▼, and press the
[ENTER]
key. Then enter the
whole number
r
and press the
[ENTER]
key.
A. Evaluating of the Binomial probabilities with the calculator TI-83plus
//
See
Handout_6a THE BINOMIAL DISTRIBUTION.doc
and
the Excel file
//
Three_Distributions.xls,
sheet
1
For evaluating of the binomial probabilities
P(x) =
n
C
x
p
x
(1 – p)
n – x
[see
formula
(6a.1) in
Handout_6a
] p
ress the keys:
[2
nd
] [DISTR],
then select
0: binompdf(
with the
up
(
) or
down
(
) arrow key, and press the
[ENTER]
key.
Then enter the numerical
values of
n
(whole number) and probability
p
(0
≤
p
≤
1) separated by comma (
,
) and
then, after the comma, enter in braces
{}
the sequence of whole values of
x
separated by
commas (
,
) in accordance with the scheme:
binompdf(n, p, {x
1
, x
2
, x
3
, …, x
k
})
and press the
[ENTER]
key. The sequence of probabilities computed for
x
1
, x
2
, x
3
, …, x
k
appears in braces
{}.
Use the
and
arrow keys to read this sequence if necessary.
Example A1.
For evaluating of the probability
P(x) =
n
C
x
p
x
(1 – p)
n – x
(6a.1) for
n = 20,
p = 0.75, x = 12
enter
binompdf(20, .75, {12})
{ .0608866892 }
Answer
1
