HP 39g Probability functions

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