(12C) Binomial Distribution

[Gamo]

This program calculate Binomial Distribution using three known variables.

Binomial Distribution formula:

f(x) = (nCx)(p^x)(1-p)^n-x

where n and x are integers,

nCx = n! / x!(n-x)! // n choose x Combination

0 ≤ x ≤ n ≤ 69 and 0 < p < 1

n = number of times experiment run
x = number we want
p = probability of one specific run

Procedure:

n [ENTER] x [ENTER] p [R/S]

Example: FIX 9

Sam says
"70% choose chicken, so 7 of the next 10 customers should choose chicken"
What are the chances Sam is right?

n = 10 // Total of 10 customers
x = 7 // 7 out of 10
P = 0.7 // 70% choose chicken

10 [ENTER] 7 [ENTER] .7 [R/S] display 0.266827932

Answer: about 27% chance

Program: Binomial Distribution

Code:


01 STO 1
02 Rv
03 STO 2
04 Rv
05 STO 3
06 RCL 1
07 RCL 2
08 Y^X
09   1
10 RCL 1
11   -
12 RCL 3
13 RCL 2
14   -
15 Y^X
16 LSTx
17  n!
18  ÷
19  x
20 RCL 3
21  n!
22  x
23 RCL 2
24  n!
25  ÷

Gamo