Statisticians use factorials when calculating potential combination and permutations and using the binomial equation. A factorial, represented by an explanation mark (!), denotes a multiplication of the sequence of descending (natural) numbers. For example, 5! equals 5*4*3*2*1. 1! = 1. And n! = n * (n-1)!
A Practice Problem!
Solve: x=10!/8!
Solution: So we can break down 10! into 10*9* 8! . We then know that 8! in the numerator cancels out the 8! in the denominator, which leaves us 10*9 in the numerator, and therefore x=90.
