# Statistics - Binomial Probability for a University

Question(1):

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

a. Compute the probability that two or fewer will withdraw.

b. Compute the probability that exactly four will withdraw.

c. Compute the probability that more than three will withdraw.

d. Compute the expected number of withdrawals.

Question (2):

Airline passengers arrive randomly and independently at the passenger-screening facility at a major international airport. The mean arrival rate is 10 passengers per minute.

a. Compute the probability of no arrivals in a 1-minute period?

b. Compute the probability of 3 or fewer arriving in a 1-minute period?

c. Compute the probability for no arrivals in a 15 second period?

d. Compute the probability of at least one arrival in a 15 second period?

For step by step detailed solution please see the attached solution file.

Thank you

https://brainmass.com/statistics/probability/statistics-binomial-probability-university-105895

#### Solution Preview

Solution (1)

Probability that one student will withdraw

Probability that two students will withdraw

Probability that two or fewer will withdraw =0.2060

Probability that ...

#### Solution Summary

For a step by step detailed solution will all the working, please download the attached solution file.

Following are mere a few steps from the solution.

Let ' p ' denote the probability that a student will withdraw without completing the course and .......

Probability that one student will withdraw ........

Probability that two students will withdraw ..........

Probability that Exactly four will withdraw ...........

Probability that three or fewer will withdraw ..............

Probability that more than three will withdraw .................

Expected number of withdrawals ....................

Solution (2):

Probability of no arrival in a one minute period ..............

Probability of 3 or fewer arrivals in one minute period ....................

Probability of no arrivals in a 15 seconds period .......................

Probability of at least one arrival in a 15 seconds period .....................