Question

A university found that 20% of its students withdraw without completing the introductory statistics course. Assume that 10 students registered for the course.

1. Compute the probability that 2 or      fewer will withdraw.
2. Compute the probability that exactly 4 will withdraw.
3. Compute the probability that more than 3 will withdraw.
4. Compute the expected number of withdrawals.

Answer 1

If x is the number of students who withdraw without completing the course
Assumption is x follows binomial distribution
a)	P(X<=2)	0.6778	BINOMDIST(2,10,0.2,1)
b)	P(x=4)	0.08808	BINOMDIST(4,10,0.2,0)
c)	P(x>3)	0.120874	1-BINOMDIST(3,10,0.2,1)
d)	Expected number		10*.2	2
	1 = Cumulative TRUE
	0 = Cumulative FALSE