Question

1.A random sample of 200 University of Manitoba students is asked whether their parents have a

university degree. What is the population of interest for this survey?

options:

all University of Manitoba students whose parents have a university degree

all University of Manitoba students

all University of Manitoba students who were included in the sample

all parents of University of Manitoba students

all parents of University of Manitoba students who have a university degree

2. A sample of residents of a small town will be selected to study the impact of rising gasoline prices. It is believed that the increase in gas prices has a different effect, depending on a person's economic status. Of the 2,000 residents of the town, 700 are classified as high income, 800 are classified as middle income and 500 are classified as low income. A research company randomly selects 70 high income residents, 80 middle income residents and 50 low income residents to respond to a survey. The combined sample of 200 residents is a:

options:

multistage sample

simple random sample

stratified random sample

convenience sample

voluntary response sample

3.A researcher wants to conduct a study involving the patients at Montreal hospitals. The researcher chooses a random sample of 3 hospitals. The researcher then chooses a random sample of 10 patients within each of these 3 hospitals. The resulting sample is a:

options:

simple random sample

multistage sample

convenience sample

stratified sample

4.A local morning radio program host invited listeners to call in and indicate whether or not they were in favour of Winnipeg developing a rapid transit corridor from downtown to the University of Manitoba. Of the 125 calls that were received, 87 indicated support for the rapid transit route. We can conclude that:

options:

This simple random sample provides a good snapshot of the opinions for and against the rapid transit system in Winnipeg.

This is a good example of an observational study, which allows us to determine the strength of support for this issue in Winnipeg.

This is a quick and inexpensive way to obtain valid information about public opinions on important issues.

Among citizens of Winnipeg there is substantial support for a rapid transit system to be developed.

Little if anything can be concluded because the sample is likely to be very biased.

5.Consider the below situations. Match each situation with the type of bias present.

options:

Matthew had no chance of being included in the phone survey because he doesn't have a phone.

Jim phoned a number he saw on the 6:00 news to respond to a survey question.

Natalie hung up the phone when she heard the person calling was from a polling firm.

**1**.Voluntary response

**2**.Undercoverage

**3**.Nonresponse

Information

Questions 6 and 7 refer to the following:

A gas station is planning to open a new car wash next year. The company will conduct an experiment to examine the effects of the type of car wash (Gold, Silver or Bronze) and the brand of soap (AutoShine or MagicSuds) on the cleanliness of a car. Each treatment will be randomly assigned to 20 (equally dirty) cars.

6.What is/are the factor level(s) in this experiment?

options:

Gold/AutoShine, Gold/MagicSuds, Silver/AutoShine, Silver/MagicSuds, Bronze/Autoshine, Bronze/MagicSuds

the gas station, the car wash and the cars

Gold, Silver, Bronze, AutoShine, MagicSuds

cleanliness of a car

type of car wash and brand of soap

7.What is the total number of cars required for this experiment?

Your Answer:

8.An experiment is to be conducted to compare the effects of six different brands of vitamins. It is believed that subjects of different ages (child, adult or senior) will respond differently to the different vitamins, so a randomized block design is used. The experimenter should use:

options:

three blocks -- each consisting of one-third of the children, one-third of the adults and one-third of the seniors.

six blocks -- one for each treatment, with two blocks consisting of only children, two blocks consisting of only adults and two blocks consisting of only seniors.

one block -- with all subjects in the same block (since we are examining only one factor)

three blocks -- one consisting of all the children, one consisting of all the adults and one consisting of all the seniors.

six blocks -- one for each treatment, each consisting of one-sixth of the children, one-sixth of the adults and one-sixth of the seniors

9.Suppose we would like to compare how Callaway brand golf clubs and Titleist brand golf clubs affect golf scores. Suppose that 100 volunteers are available for the study.

Match the proposed experimental design on the left with the type of experiment on the right.

Randomly divide the volunteers into two groups of 50 each. Every golfer will play only one round of golf. Have the first group use Callaway brand golf clubs; have the second group use Titleist brand golf clubs. Compare the golf scores of the two groups.

One weekend, each golfer will play two rounds of golf, one round using Callaway brand clubs and the other using Titleist brand clubs. Each golfer will flip a coin to decide which brand they use for Saturday's game and they will use the other brand on Sunday. Compare each golfer's scores with the two brands of golf clubs.

**1**.Completely randomized design

**2**.Matched pairs design

10.In which of the following situations would it be possible and appropriate to conduct a proper experiment, as opposed to an observational study?

a study of how changing the length of a yellow light at an intersection affects the number of cars that drive through a red light

a study of how the outdoor temperature affects the number of people who go to Grand Beach in a day

a study of how the strength of a tornado **e**ffects the financial damage caused

a study of how the size of the population of a city affects its crime rate

a study of how concussions affect the brain health of professional football players

11.True or False: Replication in experimental design is achieved by assigning each treatment to several individuals.

12. True or False: In experiments with multiple treatments, a control group is always necessary to make legitimate comparisons.

13.True or False: In a randomized block design, treatments are first randomly assigned to individuals, and then individuals are separated into blocks

14. True or False: If an experiment is well designed, we should be able to conclude that observed differences in responses are **caused** by the different treatments.

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