Probability functions

COMB

Number of combinations (without regard to order) of n

 

things taken r at a time: n!/(r!(n-r)).

 

COMB(n, r)

 

Example

 

COMB(5,2) returns 10. That is, there are ten

 

different ways that five things can be combined two

 

at a time.!

 

Factorial of a positive integer. For non-integers, ! = Γ(x +

 

1). This calculates the gamma function.

 

value!

PERM

Number of permutations (with regard to order) of n things

 

taken r at a time: n!/(r!(n-r)!

 

PERM (n, r)

 

Example

 

PERM(5,2) returns 20. That is, there are 20

 

different permutations of five things taken two at a

 

time.

RANDOM

Random number (between zero and 1). Produced by a

 

pseudo-random number sequence. The algorithm used in

 

the RANDOM function uses a seed number to begin its

 

sequence. To ensure that two calculators must produce

 

different results for the RANDOM function, use the

 

RANDSEED function to seed different starting values

 

before using RANDOM to produce the numbers.

 

RANDOM

H I N T

 

The setting of Time will be different for each calculator, so

 

using RANDSEED(Time) is guaranteed to produce a set of

 

numbers which are as close to random as possible. You

 

can set the seed using the command RANDSEED.

UTPC

Upper-Tail Chi-Squared Probability given degrees of

 

freedom, evaluated at value. Returns the probability that

 

a χ2 random variable is greater than value.

 

UTPC(degrees, value)

11-12

Using mathematical functions