6.04 Semester Assessment: AP
Statistics, Part 1 Questions 100% Well
Answered.
Consider boxplots A and B as shown here. Which of the following statements are true?
I. A has a smaller IQR than B.
II. B has more terms above its median than A.
III. A and B have the same number of terms below their medians. - Answer I only
Two boxes are placed in front of you. Box A contains 4 white and 2 black marbles, and Box B
contains 3 white and 7 black marbles. You select one of the two boxes at random and then
select one marble from that box at random. What is the probability that the marble you select is
black? - Answer 31/60
In a survey, the purpose of stratification is to: - Answer ensure that the sample is
representative of the groups of interest in the population.
Which of these statements are true of inference for one or two proportions?
I. The populations from which the samples are drawn must be at least 10 times greater than the
samples.
II. How you compute the standard error depends on whether you are constructing a confidence
interval or performing a significance test.
III. When you are doing inference for proportions, you use z-procedures because the sampling
distribution of p^ is normal. - Answer I, II, and III
A bivariate data set has x = 21, sx = 13, y = 55, sy = 27, and r = .88. What is the equation for the
regression line of y on x? - Answer ŷ = 16.57 + 1.83x
You conduct a hypothesis test for the mean of a population (H0 : p = 5) at the .05 significance
level. You establish a decision rule that you will reject this hypothesis if you get a sample mean
greater than 7. If, in reality, the population mean is 6, the probability of getting a sample mean
greater than 7 is .73. Which of the following give you the probability of a Type I error, the
probability of a Type II error, and the power of the test, respectively? - Answer .05; .27; .73
, Consider the MINITAB output shown here. You do not have access to all the data, but you have
been told that the largest five numbers are 70, 86, 86, 86, and 93. Which of the following
statements are true?
I. The data are skewed to the right.
II. This data set has more than one outlier.
III. We are justified in using z-procedures here because we are given the mean and median. -
Answer I and II only
According to David Moore in Statistics: Concepts and Controversies, a study was conducted in
Detroit where interviewers asked a sample of Black residents if they felt that they could trust
most White people, some White people, or no White people. About 35% answered "most" if
the interviewer was White, and 7% answered "most" if the interviewer was Black. This is an
example of: - Answer interviewer bias. The interviewer was in some way influencing the
response.
A well-conducted opinion poll showed that 48% of voters surveyed favored the reelection of
Congressman Porkbarrel. The people who conducted the survey reported that the poll had a
margin of error of 3.5%. Which of the following best describes this statement? - Answer Based
on the procedure by which this figure was generated, it is likely that the population proportion
is between 44.5% and 51.5%.
This table shows the probability that Joe and Elaine will each purchase a pizza of a given size.
What is the probability that at least one of the two will buy a medium pizza on their next visit to
the pizza place?
Small Medium Large
Joe .4 .5 .1
Elaine .6 .35 .05 - Answer .675
What are the mean and median, respectively, of the data shown in this table?
Value Cumulative Frequency
5 .2
6 .25
8 .40
Statistics, Part 1 Questions 100% Well
Answered.
Consider boxplots A and B as shown here. Which of the following statements are true?
I. A has a smaller IQR than B.
II. B has more terms above its median than A.
III. A and B have the same number of terms below their medians. - Answer I only
Two boxes are placed in front of you. Box A contains 4 white and 2 black marbles, and Box B
contains 3 white and 7 black marbles. You select one of the two boxes at random and then
select one marble from that box at random. What is the probability that the marble you select is
black? - Answer 31/60
In a survey, the purpose of stratification is to: - Answer ensure that the sample is
representative of the groups of interest in the population.
Which of these statements are true of inference for one or two proportions?
I. The populations from which the samples are drawn must be at least 10 times greater than the
samples.
II. How you compute the standard error depends on whether you are constructing a confidence
interval or performing a significance test.
III. When you are doing inference for proportions, you use z-procedures because the sampling
distribution of p^ is normal. - Answer I, II, and III
A bivariate data set has x = 21, sx = 13, y = 55, sy = 27, and r = .88. What is the equation for the
regression line of y on x? - Answer ŷ = 16.57 + 1.83x
You conduct a hypothesis test for the mean of a population (H0 : p = 5) at the .05 significance
level. You establish a decision rule that you will reject this hypothesis if you get a sample mean
greater than 7. If, in reality, the population mean is 6, the probability of getting a sample mean
greater than 7 is .73. Which of the following give you the probability of a Type I error, the
probability of a Type II error, and the power of the test, respectively? - Answer .05; .27; .73
, Consider the MINITAB output shown here. You do not have access to all the data, but you have
been told that the largest five numbers are 70, 86, 86, 86, and 93. Which of the following
statements are true?
I. The data are skewed to the right.
II. This data set has more than one outlier.
III. We are justified in using z-procedures here because we are given the mean and median. -
Answer I and II only
According to David Moore in Statistics: Concepts and Controversies, a study was conducted in
Detroit where interviewers asked a sample of Black residents if they felt that they could trust
most White people, some White people, or no White people. About 35% answered "most" if
the interviewer was White, and 7% answered "most" if the interviewer was Black. This is an
example of: - Answer interviewer bias. The interviewer was in some way influencing the
response.
A well-conducted opinion poll showed that 48% of voters surveyed favored the reelection of
Congressman Porkbarrel. The people who conducted the survey reported that the poll had a
margin of error of 3.5%. Which of the following best describes this statement? - Answer Based
on the procedure by which this figure was generated, it is likely that the population proportion
is between 44.5% and 51.5%.
This table shows the probability that Joe and Elaine will each purchase a pizza of a given size.
What is the probability that at least one of the two will buy a medium pizza on their next visit to
the pizza place?
Small Medium Large
Joe .4 .5 .1
Elaine .6 .35 .05 - Answer .675
What are the mean and median, respectively, of the data shown in this table?
Value Cumulative Frequency
5 .2
6 .25
8 .40
