AnswersAlgebra IIRepresenting Data and Statistics

Representing Data and Statistics — Test Answers

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1
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Which statement must be true?

A
Each distribution has a different mean and the same standard deviation.
B
Each distribution has a different mean and a different standard deviation.
C
Each distribution has the same mean and a different standard deviation.
D
Each distribution has the same mean and the same standard deviation.
2
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City planners plan to survey residents to estimate the proportion of city residents who use public transportation at least once a week. Which of the following methods describes a voluntary response survey?

A
City planners take a random sample of local homes and survey the residents.
B
City planners email a survey to all residents in the community.
C
City planners hand out surveys to parents at a youth soccer game.
D
City planners stand outside an office building and survey workers.
3

The mean of a set of credit scores is mu is equal to 690 and sigma is equal to 14 Which statement must be true about z sub 694 ?

A
z sub 694 is between 2 and 3 standard deviations of the mean.
B
z sub 694 is between 1 and 2 standard deviations of the mean.
C
z sub 694 is within 1 standard deviation of the mean.
D
z sub 694 is more than 3 standard deviations of the mean.
4

Many adults owe money from their college loans for years into their professional careers. A newspaper would like to estimate the proportion of all adults in the city who have debts from college loans. To collect data, a random sample of 300 young adults between the ages of 25 and 35 is asked, "Do you have more than 5 dollars comma 000 in current college debts?” 68 percent of those sampled reported that they do have more than 5 dollars comma 000 in college-related debts. How might this sample be biased in obtaining an estimate of all adults in the city who have college debts?

A
Because adults with college debts may be less likely to respond, voluntary response bias may cause the newspaper to underestimate the proportion of adults who have college debts.
B
Because only young adults were sampled, undercoverage bias may cause the newspaper to overestimate the proportion of all adults who have college debts.
C
Because young adults were randomly selected, this sample should provide an unbiased estimate of the proportion of adults with college debts.
D
Because some young adults may not honestly report their debts, response bias may cause the newspaper to underestimate the proportion of adults with college debts.
6

A restaurant chain would like to measure the proportion of customers who are generally satisfied with the service provided by its staff. At the end of the meal, as the check is delivered to the table, the server asks those at the table to rate their satisfaction with the service provided as "Very Satisfied,” "Satisfied,” or "Not Satisfied.” During a one-week period, 147 customers were surveyed and 135 open paren 93 percent close paren reported they were either Satisfied or Very Satisfied. How might the results be biased in obtaining an estimate of all customers who are satisfied with service?

A
Because of response bias, the survey results may overestimate the true proportion of satisfied customers.
B
Because of response bias, the survey results may underestimate the true proportion of satisfied customers.
C
Because customers were surveyed over a one-week period, the results should provide an accurate estimate of satisfied customers.
D
Because of voluntary response bias, the survey results may overestimate the true proportion of satisfied customers.
9

The mean test scores with standard deviations of four English classes are given. Class Mean Standard Deviation Mrs. Jones 89 1 point 9 Mrs. Rijo 82 1 point 4 Mr. Phan 73 3 point 4 Mrs. Scott 90 6 point 1 Which statement is most likely to be true?

A
The scores of Mr. Phan’s class are the closest to the class mean.
B
The scores of Mrs. Jones’s class are the closest to the class mean.
C
The scores of Mrs. Scott’s class are the closest to the class mean.
D
The scores of Mrs. Rijo’s class are the closest to the class mean.
11

Research suggests that students could benefit from later school starting times. A school administrative team is considering a proposal to move the starting time of the local schools one hour later than the current start time. To measure interest in the proposal, members of the team randomly select subjects attending a large high school soccer tournament played on the high school grounds on a Saturday morning. The team finds that 58 percent of those surveyed support a later high school start time. Which type of bias is most likely to be present in the survey results?

A
This is voluntary response bias because vocal supporters of later start times will be more likely to offer their opinion.
B
This is nonresponse bias because some of those selected may choose to not provide their opinion on later start times.
C
This is undercoverage bias because adults with older children are more likely to be included in the sample.
D
This is question wording bias because the phrasing of the later start times question may be confusing to some subjects.
12

Dwayne and Alisha both correctly graphed a standard normal curve. Which of the following statements is true?

A
Neither the means nor the standard deviations of Dwayne’s and Alisha’s graphs must be the same.
B
The means of Dwayne’s and Alisha’s graphs must be the same but not the standard deviations.
C
Both the means and the standard deviations of Dwayne’s and Alisha’s graphs must be the same.
D
The standard deviations of Dwayne’s and Alisha’s graphs must be the same but not the means.
13

A citizen wants to propose to the city council extending the hours at the local public library on some weekdays. To measure support for extended hours, the citizen visits neighborhood homes and asks adults the following: "Would you agree that the closing time of the library should be extended by one hour on weekdays to accommodate working families?” Of the 212 adults surveyed, 86 percent agreed with the statement. Which of the following statements about the results is true?

A
The survey suffers from voluntary response bias and may not estimate true support for the extended hours.
B
The survey suffers from question wording bias and may not represent true support for the extended hours.
C
The 86 percent support provides substantial evidence that the library hours should be extended.
D
More families should be asked the same question to be sure of community support.
14

An automotive service center would like feedback on its customer service. Each customer receives a printed card after they pay for services with a short survey on which customer service is ranked on a scale from 1 (least satisfied) to 5 (most satisfied). Customers can then choose to submit the card in a box on their way out of the store. The store manager finds that 140 cards were filled out in the past week, with an average customer satisfaction score of 2 point 4 7 Which type of bias is most likely to be present in the survey results?

A
This is undercoverage bias because some types of customers may not have received cards.
B
This is response bias because customers may not be truthful about their experience with customer service.
C
This is question wording bias because the customer service score levels may not be clear to customers.
D
This is nonresponse bias because many customers may choose to not fill out the cards.
15

Which normal distribution has the greatest standard deviation?

A
Image with description A normal distribution is shown on x-axis with markings from 16 to 56 in increments of 8. The curve has a peak at 32 and hits the axis at 28 and 38.
B
Image with description A normal distribution is shown on x-axis with markings from negative 8 to 40 in increments of 8. The curve has a peak at 16.
C
Image with description A normal distribution is shown on x-axis with markings from 80 to 120 in increments of 8. The curve has a peak at 96 and hits the x-axis at 75 and 115.
D
Image with description A normal distribution is shown on x-axis with markings from 40 to 80 in increments of 8. The curve has a peak at 60 and hits the x-axis at 48 and 72.
16

For a standard normal distribution, which of the following expressions must always be equal to 1 ?

A
cap p times open paren z is less than or equal to negative A close paren minus cap p times open paren negative A is less than or equal to z comma z is less than or equal to A close paren plus cap p times open paren z is greater than or equal to A close paren
B
cap p times open paren z is less than or equal to negative A close paren minus cap p times open paren negative A is less than or equal to z comma z is less than or equal to A close paren minus cap p times open paren z is greater than or equal to A close paren
C
cap p times open paren z is less than or equal to negative A close paren plus cap p times open paren negative A is less than or equal to z comma z is less than or equal to A close paren plus cap p times open paren z is greater than or equal to A close paren
D
cap p times open paren z is less than or equal to negative A close paren plus cap p times open paren negative A is less than or equal to z comma z is less than or equal to A close paren minus cap p times open paren z is greater than or equal to A close paren
18

A factory produces plastic parts used to fit in car dashboards. It is important that the parts are produced with the correct dimensions, or they may not fit in the car dashboard. To ensure that the parts are being made correctly, a sample of parts is checked and measured each day. Which of the following methods would not represent a convenience sample?

A
At the end of the day, a container of 30 parts is inspected and measured.
B
Right after lunch, the first 25 parts are inspected.
C
Fifty parts are chosen at random from the many parts made each day.
D
The first 20 parts produced after the start of the day are inspected and measured.
19

The mean game scores and standard deviations of four seasons of a football team are given. Season Mean Standard Deviation 2005 19 3 point 5 2006 21 2 point 8 2007 12 1 point 0 2008 9 4 point 0 Which statement must be true?

A
The game scores of season 2007 have a greater spread than the game scores of season 2005.
B
The game scores of season 2006 have a greater spread than the game scores of season 2008.
C
The game scores of season 2005 have a greater spread than the game scores of season 2006.
D
The game scores of season 2006 have a greater spread than the game scores of season 2005.

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