Problem 10 Suppose that 85 of graduating students attend the

(Problem 10) Suppose that 85% of graduating students attend their graduation. A group of 22 graduating students is randomly chosen.  Let X be the number of students that attend graduation.  As we know, the distribution of X is a binomial probability distribution.  Answer the following:

(a) What are the number of trials (n)?

(b) What is the probability of successes (p)?

(c) What is the probability of failures (q)?

(d) How many students are expected to attend graduation?

Solution

a) here number of trails = 22

b) probability of success as given = 85% = 0.85

c) probability of failure = 1 -0.85 = 0.15

d)expectation will be 0.85*22 = 18.7 = 19

e) probability of 18 = 22C18*(0.85)^18*(0.15)^4 = 0.198