Question

A particular telephone number is used to receive both volce calls and fax messages. Suppose that 25 of the incoming calls involve fax messages, and consider a sample of incoming calis (Round your answers to three decimal places.) (a) What is the probability that at most of the calls involve a fax message? (b) What is the probability that exactly 4 of the calls involve a fax message? (c) What is the probability that at least 4 of the calls involve a fax message? (d) What is the probability that more than 4 of the calls involve a fax message?

Answer 1

Solo given that the data wy the Incoming cally involved far of * Suppose that 25.). messages and 25 Incoming calls Sample Considered a) finding the probability that at most म x = No fax message of Cally Involve x XN BhChip) P(x= x). ncap n=25 = 25.1. = 25 n-N ใน ; X=0,1,2--- n 100 2 0.25 q=1-P - 1-0.25 = 0.75 4 8(x24) = 2 nce x non Pr

asc, Co.es) °(0.75) "705c, (0.2) '(0.75)9425&co.230.7. + asg Couds3°C0- 45) ? 4+ 25cy, (0.2534 (0.75) 21 0.00075 + 0.00627+ 0.02508 + 0.06610+ 0.11752 P (X=4) = 0.21372 Finding the probability that Enactly 4 of Calls P(x=4) 0.1(752684 the b ) atlegt u of the Colly c) finding the probability of Incolue fax messages p(x>4) = 1 - P(x<+) -1-(p(x=0) +P(x=1) +P(X=2) +p(x-3) ] !-( 0.00075+ 0.00627 +0.08.08 + 0.06410 ] = 0.9038 than 4 of the More that a) Finding the Probability Calls involue a fax message 8(X < x) = 0.0962140