Question

Imagine you flip a coin onto a flat surface. You have a one-in-six thousand chance of the coin landing on its edge. You want to get this elusive result three times, so you flip the coin repeatedly until you succeed. Consider a random variable J that corresponds to the trial number where you have flipped your third "edge" result. Write expressions for the following probabilities (you don't have to evaluate them numerically) a) P(J= 18,000) b) P(19,998 < J20,001) c) P(J 3) d) P(4J)

Answer 1

一ㄧ一Here.. T: No. of trials required toget the coin la edge p pxzob of toin laoding e Coio land on ii's edge Negative Bioomial diihib with parameters 5999 6000 60o0

otherwise 18o0D 3 6000 x 600o て3xSggge 00D 6 0 0 6

( 19,99 20,001) using centic ltmit theozem then ECT / 2000 I-ECT) VLT P(T 3 6 00 D

ECT rt-チナーー