Quiz # 4 Quarter 3 - Form A

Determine whether the strategy described results in a fair decision. Explain. (2 marks)

An art teacher wants to choose 3 of his 20 students at random to clean the paintbrushes this week. As students arrive for class on Monday, he has them roll a number cube. The first 3 students to roll an even number are chosen.

Use the random number line below. (3marks)

A worker at a daycare center wants to select 5 of the 42 children at random to take on a nature walk. She assigns a two-digit number from 01 to 42 to each child. What are the numbers of the children chosen for the nature walk? Use the random number line below.

67120 69656 32394 25564 95187 59758 06641

Describe a simulation.(3 marks)

A magazine company gives away either a blue T-shirt or a white T-shirt with every magazine subscription. The T-shirts are equally and randomly distributed. Describe a simulation that you could use to predict the number of magazine subscriptions you would have to buy to get at least one T-shirt of each color

A company is testing a new type of office chair that claims to relieve back pain. Thirty volunteers with back pain are given the new chair, and 30 volunteers with back pain continue sitting in their current chair. After a month, the 60 volunteers are surveyed.

a) Find the probability that a volunteer improved given he or she used the new chair ( 2marks)

b) Now find the probability that a volunteer improved given he or she used the current chair. ( 2marks)

c) Based on the results in the contingency table, the company decides to market the chair as an effective means to relieve back pain. Did the company make a good decision? ( 2marks

Use a tree diagram to solve the following problem.( 4 marks)

A car insurance company compiled the following information from a recent survey.

· 75% of drivers carefully follow the speed limit.

· Of the drivers who carefully follow the speed limit, 80% have never had an accident.

· Of the drivers who do not carefully follow the speed limit, 65% have never had an accident.

Q: What is the probability that a driver does not carefully follow the speed limit and has never had an accident? ( SHOW YOUR DIAGRAM)

6. Using two -way tables to find conditional probability (6 marks)

1. P(black | acoustic)

2. P(blue | electric)

3.P( acoustic)