A lbrary subscrlbes to two different weekly news magazlnes, each of which is sup
ID: 3042006 • Letter: A
Question
A lbrary subscrlbes to two different weekly news magazlnes, each of which is supposed to arlve In Wednesday's mall. In actuallty, each one may arrive on Wednesday, Thursday, Friday, or Saturday. Suppose the two arrive independently of one another, and for each one p Wed 0.2 p Thurs 0.38, P Fri -0.25, and P Sat -0.17. Let the number of days beyond Wednesday that it takes for both magazines to arrive (so possible Y values are 0, 1, 2, or 3). Compute the pmf of Y. [Hint: There are 16 possible outcomes; Y(W,W)-0, YF, Th)-2, and so on. 1 (Enter your answers to four decimal places.) 3 P() 004 0.8875 X 2964Explanation / Answer
Following table shows the possible outcomes and corresponding probabilites:
Following table shows the probability distribtuion of Y :
Outcome Probability Y WW 0.04 0 WTh 0.076 1 WF 0.05 2 WS 0.034 3 ThW 0.076 1 ThTh 0.1444 1 ThF 0.095 2 ThS 0.0646 3 FW 0.05 2 FTh 0.095 2 FF 0.0625 2 FS 0.0425 3 SW 0.034 3 STh 0.0646 3 SF 0.0425 3 SS 0.0289 3