Math 9 LG 17 Practice Quiz #3

Name:

Multiple Choice
Identify the choice that best completes the statement or answers the question.

Jon’s coworkers pool their money so they can buy more lottery tickets and increase their chance of winning.
Is their decision based on theoretical probability, experimental probability, or subjective judgment?

a.	A combination of theoretical and experimental probability
b.	Theoretical probability
c.	Experimental probability
d.	Subjective judgment

The chance of winning a prize in a lottery was 15%.
Claudia was having a lucky day, so she bought a ticket.
Was her decision based on theoretical probability, experimental probability, or subjective judgment?

a.	Subjective judgment
b.	Experimental probability
c.	Theoretical probability
d.	A combination of experimental probability and subjective judgment

Marjorie wanted to collect information about the sports her classmates were interested in. She prepared a 10 min questionnaire which she gave to her classmates the day before the final math exam.
In this survey, which of the following might be a problem with this question?

i)      Privacy
ii)      Timing
iii)      Cost
iv)      Cultural sensitivity

iii

Marissa asked everyone in her class what chocolate bar they liked best.
Before her next test, she gave her teacher the chocolate bar he’d said he liked best.
What was a problem with Marissa’s survey?

i)      Use of Language
ii)      Cost
iii)      Ethics
iv)      Timing

iii

A city council wants to know if residents think there is a need for more library facilities.
What is the population they are interested in surveying?

i)      Students who use the libraries
ii)      City residents
iii)      People who use the libraries
iv)      People who work at the libraries

iii

A college wants to estimate the number of high school students who will enrol in September.
Which data collection method would provide the most accurate information?

i)      Survey a sample of grade 12 students from one local high school
ii)      Survey a sample of grade 12 students from all the local high schools
iii)      Survey all grade 12 students from the local high schools
iv)      Survey all grade 12 students from one local high school

iii

A baker wants to check the quality of the muffins he bakes each day.
Which of the following data collection methods would provide the most accurate information?

i)      Test one muffin from each batch
ii)      Test all the muffins in the first batch
iii)      Test all the muffins in a random batch
iv)      Test all the muffins in the last batch

iii

A mobile phone company wants to know if its customers would be willing to pay a higher monthly fee for a plan that would cover international calls to Europe. To gather data, they make a list of cell phone numbers that regularly make calls to Europe and use a computer program to randomly select numbers from this list to call and survey. Which sampling method did the company use?

a.	Simple random sampling	c.	Self-selected sampling
b.	Systematic sampling	d.	Convenience sampling

A travel company specializes in arranging two-week holidays to the resorts of Beachland, Seaview, and Hillside. The owner of the company wanted to gauge customer satisfaction with the service. He made a list of customers who had visited one of the resorts over the last year and called every 10th customer on the list. Which sampling method did the owner use?

a.	Systematic sampling	c.	Cluster sampling
b.	Convenience sampling	d.	Stratified random sampling

10.

The administrator of a dance and fitness studio wants to know if there is interest in having more evening classes available. He surveys everyone who participates in yoga classes to see what they think. Which sampling method does he use?

a.	Self-selected sampling	c.	Simple random sampling
b.	Stratified random sampling	d.	Cluster sampling

Short Answer

11.

Andrew read that far more people are injured in car accidents than in minivan incidents, so he plans to purchase a minivan rather than a car.
What assumption is Andrew making?

12.

Darrell buys coffee in his local coffee shop at the same time every day.
He notices that, of the 20 people in the shop, 14 purchased a medium coffee.
He concludes that 70% of the coffees sold at the shop are medium coffees.
What assumption did Darrell make?

13.

Anita surveyed her classmates to see if they were interested in a Christmas gift exchange.
How might she have problems with cultural sensitivity? Explain.

14.

Ms. Calder had her students complete a questionnaire on the number of hours they spent studying in a week. How might timing affect her results?

15.

The owners of a chain of fast food restaurants want to know if customers are satisfied with the restaurant chain. They set up a Web site where customers can enter a code from their receipt and then rate the restaurant.
Are the data collected from a sample or a population?

16.

A materials engineer tests a certain type of cell phone to see how resistant the phone is to high temperatures. Does he collect data from a sample or a census?

17.

Wayne asked the boys in his grade 9 class whether they watched NHL hockey on TV.
12 out of the 15 boys said they watched NHL hockey on TV.
Wayne concluded that 80% of grade 9 students watched NHL hockey on TV.
What, if anything, is wrong with Wayne’s claim?

18.

The principal of a large high school wants to know how grade 9 students in his school feel about mathematics, so all students in one grade 9 math class were surveyed.
What is a potential problem with this sampling method?

19.

A local radio station invites its listeners to call in and say whether they think schools should provide perks, such as free MP3 players, for students with perfect attendance. Will the selected sample represent the population?

20.

An airline manager wants to assess customer satisfaction at check-in. She decides to survey every 30th person who checks in for one week. Will the selected sample represent the population?

Problem

21.

At 10 am, Naïna and Claire arrived at a ticket office to buy tickets for a concert.
The line up was long, so they considered going to the gym and returning at 1 pm.

a) What assumptions would suggest this was a good idea?
b) What assumptions would suggest this was not a good idea?

22.

Josh wants to find out how much, on average, grade 9 students spend on food each month.

a) Identify potential problems he may encounter related to privacy, ethics, language, and timing.
b) For each potential problem in part a, suggest how Josh could avoid it.

23.

Alvaro and Esinam are in the same grade 9 class. Alvaro sends an email survey to 15 of his classmates and finds that 30% of them have experienced cyber-bullying. He reports that 30% of the grade 9 students have experienced cyber-bullying. Esinam surveys all the students in grade 9 and finds that 16% of them have experienced cyber-bullying.
a) Whose conclusion is more likely to be valid? Explain.
b) Why might the other student’s conclusion not be valid?

24.

Four students have been hired to prepare gift bags for a large conference. Each gift bag has to contain the same five items and students are expected to fill 20 bags per hour. The quality control officer ensures the job is completed correctly and on time. Describe a sampling method you could use to ensure the bags contain the correct items, and are filled at an appropriate rate.