Chapter 17 - Probability Applications; The Mth/Probability.. Sub-Menu - Part 1; Factorials, Combinations, And Permutations - HP 49g+ User Manual

Chapter 17
Probability Applications
In this Chapter we provide examples of applications of calculator's functions
to probability distributions.

The MTH/PROBABILITY.. sub-menu - part 1

The MTH/PROBABILITY.. sub-menu is accessible through the keystroke
sequence „´.
With system flag 117 set to CHOOSE boxes, the
following list of MTH options is provided (see left-hand side figure below).
We have selected the PROBABILITY.. option (option 7), to show the following
functions (see right-hand side figure below):
In this section we discuss functions COMB, PERM, ! (factorial), RAND, and
RDZ.

Factorials, combinations, and permutations

The factorial of an integer n is defined as: n! = n
definition, 0! = 1. Factorials are used in the calculation of the number of
permutations and combinations of objects.
permutations of r objects from a set of n distinct objects is
P =
n r
Also, the number of combinations of n objects taken r at a time is
n
n (
r
n ( n − 1 )( n − 1 )...( n − r + ) 1
n 1 )( n 2 )...( n r
r !
⋅ ⋅ ⋅ ⋅
(n-1) (n-2)...3 2
For example, the number of
= n /( ! n − r )!
) 1 n !
r ( ! n r )!
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