Upon being dealt 5 cards from a standard 52-card deck, what is the probability of receiving exactly 4 of a kind and why? Round the answer to the nearest hundred thousandth.

52 * 3 * 2 * 1 = total possibilities for a four of a kind = A

52 * 51 * 50 * 49 = total possibilities for any hand = B

Probability of four of a kind = A / B

= (52 * 3 * 2 * 1) / (52 * 51 * 50 * 49)

=.000048