G. 7:Probability
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Not all options are given in the entry format. Options that are used frequently will be included, but others are omitted from the table. For a complete format listing, you can check the TI89 manual. Results in complex mode are not covered. They can be found in the manual.
Operation

Entry Format

Explanation

Screen

1:!  expression1!  Returns the factorial
of the argument. The values must be nonnegative whole numbers. 

2:nPr  NPR(expression1,expression2)  NPR(
) is the number of permutations of expression1 things taken expression2 at a time. 

3:nCr  NCR(expression1,expression2)  NCR(
) is the number of combinations of expression1 things taken expression2 at a time. 

4:rand  rand([n])  n is an integer, but
not 0. If n is omitted, the next random number between 0 and 1 in the sequence is returned. 

5:randNorm  randNorm(mean,sd)  Returns a decimal
number from the normal distribution. 

6:RandSeed  RandSeed number  If number=0,
sets the seeds to the factory defaults for the random number generator. If the number is not 0, then two seeds are generated and stored in system variables seed1 and seed2. 

7:randMat  randMat(numRows,numColumns)  Returns a matrix of
integers between 9 and 9 of the specified dimension. 

8:randPoly  randPoly(var,order)  Returns a polynomial
in var of the specified order. The coefficients are random integers in the range 9 to 9. The leading coefficient will not be 0. 