Probability Functions; Factorial; Gamma; Probability - HP 33s User Manual

Probability Functions

Factorial

To calculate the factorial of a displayed non-negative integer x (0 x 253), press
¹ * ,
(the left–shifted key).

Gamma

To calculate the gamma function of a noninteger x , ( x ), key in ( x – 1) and press
¹ *
. The x ! function calculates ( x + 1). The value for x cannot be a negative
integer.

Probability

Combinations
To calculate the number of possible sets of n items taken r at a time, enter n first,
¹ x
, then r (nonnegative integers only). No item occurs more than once in a
set, and different orders of the same r items are not counted separately.
Permutations
To calculate the number of possible arrangements of n items taken r at a time, enter
¹ {
n first, , then r (nonnegative integers only). No item occurs more than
once in an arrangement, and different orders of the same r items are counted
separately.
Seed
To store the number in x as a new seed for the random number generator, press
º §
.
Random number generator
º ©
To generate a random number in the range 0 x 1, press . (The
number is part of a uniformly–distributed pseudo–random number sequence. It
passes the spectral test of D. Knuth, The Art of Computer Programming, vol. 2,
Seminumerical Algorithms , London: Addison Wesley, 1981.)
4–14
Real–Number Functions