Binomial Probability Worksheet
Mean=
np
= ×
St. dev=
(1 )np p= ××−
Given the number of trials and the probability of success, find the mean, standard deviation, and
the probability of:
1.
,2.0,
12 == pn
2.
,5.0,20 == pn
3.
,05.0,11 == pn
find P(3 failures)
4.
,35.0,6 == pn
find P(at least 3 successes)
Find the probability of the Binomials given.
5. In a history class, Colin and Diana both write a multiple choice quiz.
There are 10 questions. Each question has five possible answers. What is the probability that
a) Colin will pass the test if he guesses an answer to each question.
b) Diana will pass the test if she studies so that she has a 75% chance of answering
each question correctly.
c) Expected number of correct guesses for Colin.
d) Expected number of correct guesses for Diana.
6. The manufacturing sector contributes 17% of Canada’s gross domestic product. A
customer orders 50 components from a factory that has a 99% quality production rate (99%
of the products are defect-free). Find the probability that:
a) none of the components in the order are defective
b) there is at least one defective product in the order.
c) There are at least two defective products in the order.
d) Expected number of defective parts.
7. Approximately 3% of the eggs in a store are cracked. If you buy two dozen eggs, what is
the probability that
a) none of your eggs are cracked
b) at least one of your eggs is cracked
c) exactly two of your eggs are cracked
d) Expected number of cracked eggs
e) Expected number of uncracked eggs
8. The probability the Tim will sink a foul shot is 70%. If Tim attempts 10 foul shots, what is
the probability that
a) he sinks exactly 8 shots
b) he sinks at least 8 shots
c) he sinks at most 2 shots
d) he sinks between 5 and 7 shots, inclusive.
e) Expected number of sinks out of 10 foul shots
