07 Jan the mean number

MATH225 Statistical Reasoning for the Health Sciences

Week 2 Quiz

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 for headache

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 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.

15,30,28,19,14,18,28,19,10,19,10,24,14,18,24,27,10,18,16,23

Lower Class Limit Upper Class Limit Frequency

$$10 $$15 $$6

$$16 $$21 $$7

$$22 $$27 $$4

$$28 $$33 $$3

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 $$0.12

2 0.23 $$0.35

3 0.34 $$0.69

4 0.31 $$1

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?

A histogram has a vertical axis labeled Frequency and has a horizontal axis that measures six categories of rainbow trout weight (in pounds). Reading from left-to-right, the weight and frequency of each category are: 4.5 to 6.5 has frequency of 4, 6.5 to 8.5 has frequency 5, 8.5 to 10.5 has frequency 7, 10.5 to 12.5 has frequency 3, 12.5 to 14.5 has frequency 1, 14.5 to 16.5 has frequency 2.

Question 13Describe the shape of the given histogram.

A histogram has a horizontal axis from 0 to 16 in increments of 2 and a vertical axis labeled Frequency from 0 to 10 in increments of 2. The histogram contains vertical bars of width 1 starting at the horizontal axis value 0. The heights of the bars are as follows, where the left horizontal axis label is listed first and the frequency is listed second: 0, 0; 1, 0; 2, 6; 3, 6; 4, 7; 5, 6; 6, 6; 7, 6; 8, 7; 9, 6; 10, 6; 11, 6; 12, 6; 13, 7; 14, 0; 15, 0.

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.

Stem123Leaf002444788889225578344555666799

There are $$12 values in the data set which are greater than or equal to 10 and less than or equal to 19. There are $$12values in the data set which are greater than or equal to 30 and less than or equal to 39. There are $$6 values in the data set which are greater than or equal to 20 and less than or equal to 29.

Question 15The bar graph below shows the number of boys and girls in different classes.

A bar graph has a horizontal axis labeled Classes and a vertical axis labeled Students from 0 to 16 in increments of 2. There are two vertical bars above each horizontal axis label, with the bar on the left representing Boys and the bar on the right representing Girls. The bars have heights as follows, with the horizontal axis label listed first and the bar heights listed second from left to right: Mrs. Brown, 10 and 15; Ms. James, 11 and 12.

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?

A line graph has an x-axis labeled Square Footage (in hundreds of feet) in increments of one, and a y-axis labeled Number of TV’s in increments of one. Beginning at the point start parentheses 6,2 end parentheses, a line increases to the point start parentheses 8.5,3 end parentheses. The line remains constant to the point start parentheses 10,3 end parentheses. The line then increases, passing through the point start parentheses 12,5 end parentheses and continues increasing until it reaches the point start parentheses 16,6 end parentheses.

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$838?939

0.10 0.10

$940-1041$940?1041

0.15 0.25

$1042-1143$1042?1143

0.20 0.45

$1144-1245$1144?1245

0.05 $$0.5027

$1246-1347$1246?1347

0.25 0.75

$1348-1449$1348?1449

0.25 1.00

Question 18 The bar graph below shows the number of men and women in different clubs.

A side-by-side bar graph has a horizontal axis labeled Clubs with the classes Drama and Computer and a vertical axis labeled Students from 0 to 16 in increments of 2. Two vertical bars are above each horizontal axis label with the left bar representing Men and the right bar representing Women. The bars have heights as follows, with the horizontal axis label listed first and the bar height listed second: Drama, 11 and 16; Computer, 14 and 14.

How many total students are in the Drama Club?

Question 19 An English professor asks her students who their favorite character is in the novel they are reading. What is the level of measurement of the data?

nominal

ordinal

interval

ratio

Question 20Jessica is keeping track of her favorite stock’s price. The line graph below shows the data.

A line graph titled Stock Price Over Time has a horizontal X-axis labeled Days from 0 to 5 in increments of 1 and a vertical Y-axis labeled Price from 0 to 14 in increments of 2. The graph consists of 6 plotted points connected by line segments from left to right. The coordinates of the plotted points are at left-parenthesis 0 comma 13 right-parenthesis, left-parenthesis 1 comma 3 right-parenthesis, left-parenthesis 2 comma 10 right-parenthesis, left-parenthesis 3 comma 4 right-parenthesis, left-parenthesis 4 comma 14 right-parenthesis, and left-parenthesis 5 comma 12 right-parenthesis.

At what day was the price 10?

$$day 2

Question 21A set of data is summarized by the stem and leaf plot below.

Stem1234Leaf001122234446677023344455556789912345667789011223333444555799

The value 10 appears $$2 time(s) in the data set. The value 14 appears $$3 time(s) in the data set.

Question 22 Describe the shape of the given histogram.

A histogram has a horizontal axis from 0 to 16 in increments of 2 and a vertical axis labeled Frequency from 0 to 10 in increments of 2. The histogram contains vertical bars of width 1 starting at the horizontal axis value 0. The heights of the bars are as follows, where the left horizontal axis label is listed first and the frequency is listed second: 0, 0; 1, 1; 2, 1; 3, 2; 4, 3; 5, 5; 6, 7; 7, 8; 8, 8; 9, 6; 10, 5; 11, 3; 12, 2; 13, 2; 14, 1; 15, 0.

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 25In 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?

the group that received the anxiety-reduction pill

the psychological study

all the people in the study

the group that received the inert pill