Question

Assig12. A local university reports that 15% of their students take their general education courses on a pass/fail basis. Assume that fifteen students are registered for a general education course. a. What is the expected number of students who have registered on a pass/fail basis? b. What is the probability that exactly five are registered on a pass/fail basis? c. What is the probability that more than four are registered on a pass/fail basis? d. What is the probability that less than two are registered on a pass/fail basis?

Answer 1

Solutions of Girent n=15 p=0.15 XNB(hip) plx=x) = 6) -p 9-26 x20, 1, 2, -n so. ELX) = = npr . - 15X0.15 E(X) = 2:25) 2.25 is the expected number of students who have registered on a pass / fail basis. plx=s) = (15) Cols (1-015 = 0.0449 P(X=5) = 0.0449 0.0a4g is the probability that exactly fire on a pussfas) basis. are registered

p(x) = |-(xt) =)4P(X=o) + P(x=12+ P(X=2)+p(433) +P(X=4) 0.0873 +0.2312+ 0.2856 +0.2184 +0.11562 -1-0.9382 P(x4 = 0.06181 four are registered 0.0618 is the probability that more than two on a pass / fall basis. - pcxc2) = P(X=o) + P(x=)) = 0.0873 +0.23)2 = 0.3185 pix(2) = 0-3185) less than two are registered 10.3185 is the probability that on a pass/ fail basis.