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# (Solved) MATH225N Week 2 Quiz

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QUESTION 1

A company has developed a wristband for monitoring blood sugar levels without requiring direct blood samples. It is interested in demonstrating the accuracy of the device for governmental approval and has decided to test the claim “The glucose level reported by the wristband is within 10% of a standard blood test result.” Which of the following data collection processes would be appropriate? Select only one answer choice.

• Choose a random sample of employees at lunchtime and measure their blood sugar using both the wristband and a standard blood test.
• Choose a random sample of people from the local area and random times throughout the day and measure their blood sugar using both the wristband and a standard blood test.
• Choose a random sample of people from the local area and random times and measure their blood sugar using the wristband. Choose another random sample of people and random times and measure their blood sugar using the standard blood test.
• Go to a hospital and have the doctors choose a random sample of patients to be tested at random times using both the wristband and the standard blood test.

QUESTION 2

A farmer divided his piece of land into 4 equivalent groups. The quality of the soil is the same across the 4 groups of land. He planted the same crop in all 4 groups of land and recorded the yield of the crop in all 4 groups for a 4 week period. Is the study observational or experimental? If it is an experiment, what is the controlled factor?

• The study is an observational study.
• The study is an experiment. The controlled factor is the 4 week observation period.
• The study is an experiment. The controlled factor is the land.
• The study is an experiment. The controlled factor is the growth of the crops.

QUESTION 3

To test the effectiveness of a drug proposed to relieve symptoms of headache, physicians included participants for a study. They gave the drug to one group and a drug with no therapeutic effect to another group. Which group receives the placebo?

• the physicians
• the group that received the drug with no therapeutic effect
• all of the people in the study

QUESTION 4

Matthew has created a survey to test whether or not gender has any effect on political party associations. What is the explanatory variable in this situation?

• the number of people surveyed
• political party associations
• gender
• none of the above

QUESTION 5

Is the statement below true or false?

Continuous data are the type of quantitative data that is the result of measuring.

• True
• False

QUESTION 6

A doctor notes her patient’s temperature in degrees Fahrenheit every hour to make sure the patient does not get a fever. What is the level of measurement of the data?

• nominal
• ordinal
• interval
• ratio

QUESTION 7

Karen wants to estimate the mean number of siblings for each student in her school. She records the number of siblings for each of 200 randomly selected students in the school. What is the sample?

• the 200 randomly selected students
• the specific number of siblings for each randomly selected student
• all the students in the school
• the mean number of siblings for the randomly selected students
• the mean number of siblings for all students in the school

QUESTION 8

True or False? In reference to different sampling methods, systematic sampling includes the steps: divide the population into groups; use simple random sampling to identify a proportionate number of individuals from each group.

• True
• False

QUESTION 9

While standing on a highway overpass, Jennifer wonders what proportion of the vehicles that pass on the highway below are trucks. The highway has 4 lanes running in each direction. Jennifer is only interested in the proportion of vehicles that pass over the course of the hour that she spends there. Which of the following sampling methods would be best for Jennifer to employ?

• Obtain a cluster sample by randomly selecting 3 of the 36 numbers and letters that might be at the beginning of a license plate, and select every vehicle whose license plate starts with one of those 3 numbers or letters.
• Obtain a convenience sample by watching 1 lane and selecting every vehicle that passes in that lane.
• Obtain a systematic sample by selecting every 20th vehicle that passes (in any lane and going in any direction).
• Obtain a stratified sample by, during every minute, spending 712 second watching each of the 8 lanes and selecting the last vehicle that passes during the time it is being watched (or the first vehicle after that time if no cars pass during that time).

QUESTION 10

As a member of a marketing team, you have been tasked with determining the number of DVDs that people have rented over the past six months. You sample twenty adults and decide that the best display of data is a frequency table for grouped data. Construct this table using four classes.

15,31,28,19,14,18,28,19,10,19,10,24,14,18,24,27,10,18,16,23

Lower Class Limit              Upper Class Limit             Frequency

QUESTION 11

The values and relative frequencies for a set of data are shown below.

Complete the cumulative relative frequency table.

Data Value          Relative Frequency         Cumulative Relative Frequency

1                                  0.12

2                                  0.23

3                                  0.34

4                                  0.31

QUESTION 12

The histogram below displays the weights of rainbow trout (in pounds) caught by all visitors at a lake on a Saturday afternoon. According to this histogram, which range of weights (in pounds) contains the lowest frequency? Answer: greater than ….. but less than ….

QUESTION 13

Describe the shape of the given histogram. • uniform
• unimodal and symmetric
• unimodal and left-skewed
• unimodal and right-skewed
• bimodal

QUESTION 14

A set of data is summarized by the stem and leaf plot below. There are…..values in the data set which are greater than or equal to 10 and less than or equal to 19. There are… values in the data set which are greater than or equal to 30 and less than or equal to 39. There are…. values in the data set which are greater than or equal to 20 and less than or equal to 29.

QUESTION 15

The bar graph below shows the number of boys and girls in different classes. How many total students are in Ms James’s class? Do not include the units in your answer.

QUESTION 16

The line graph shown below represents the number of TVs in a house by square footage (in hundreds of feet). According to the information above, which of the following is an appropriate analysis of square footage and TVs? • From the data, the number of TVs doubled from a square footage of 8.5 and 10.
• From the data, there is a steady decrease in the square footage and number of TVs.
• From the data, there is a steady increase in the square footage and number of TVs.
• From the data, when the square footage is between 8.5 and 10, the number of TVs remains the same.

QUESTION 17

Ashley is reviewing past monthly credit card statements.  The statements are summarized in the relative frequency table below.

What is the cumulative relative frequency of credit card statements that are \$1245 or less?

Statement Balance          Relative Frequency         Cumulative Frequency

838-939                                   0.10                             0.10

940-1041                                0.15                             0.25

1042-1143                               0.20                             0.45

1144-1245                               0.05

1246-1347                               0.25                             0.75

1348-1449                               0.25                             1.00

QUESTION 18

The bar graph below shows the number of men and women in different clubs. How many total students are in the Drama Club?

QUESTION 19

An English professor asks her students who their favourite character is in the novel they are reading. What is the level of measurement of the data?

• nominal
• ordinal
• interval
• ratio

QUESTION 20

Jessica is keeping track of her favourite stock’s price. The line graph below shows the data.

A line graph with plotted points At what day was the price 10?

QUESTION 21

A set of data is summarized by the stem and leaf plot below. The value 10 appears —- time(s) in the data set. The value 14 appears —-time(s) in the data set.

QUESTION 22

Describe the shape of the given histogram. • uniform
• unimodal and symmetric
• unimodal and left-skewed
• unimodal and right-skewed
• bimodal

QUESTION 23

A data set is summarized in the frequency table below. Using the table, determine the number of occurrences of values greater than or equal to 6.

Value    Frequency

0              7

1              5

2              3

3              2

4              3

5              5

6              0

7              9

8              1

9              6

10           4

Give your answer as a single number. For example if you found the number of values was 23, you would enter 23.

QUESTION 24

Timothy wants to estimate the mean number of siblings for each student in his school. He records the number of siblings for each of 75 randomly selected students in the school. What is the statistic?

• the specific number of siblings for each randomly selected student
• the 75 randomly selected students
• the mean number of siblings for the randomly selected students
• the mean number of siblings for all students in the school
• all the students in the school

QUESTION 25

In a psychological study aimed at testing a drug that reduces anxiety, the researcher grouped the participants into 2 groups and gave the anxiety-reduction pill to one group and an inert pill to another group. Which group receives the placebo?