Psych 311 Exam Solved Correctly
A researcher asks participants to estimate the height (in inches) of a statue that was in
a waiting area. The researcher records the following estimates: 40, 46, 30, 50, and 34. If
the researcher removes the estimate of 40 (say, due to an experimenter error), then the
value of the mean will____ (Hint: Calculate the mean first!)
a) decrease
b) increase
c) remain the same
d) become negative - Answer- C
Researchers measure data in a ________ to learn more about individuals in the larger
_______ of interest.
A) sample; population
B) statistic; inference
C) population; sample
D) inference; statistic - Answer- A
Which of the following is true about the computational formula for variance?
A) The computational formula will always produce the same solution as the definitional
formula (give or take rounding errors).
B) It is a short-cut method for calculating variance when the population or sample size is
large.
C) It is derived mathematically from the definitional formula.
D) all of the above - Answer- D
Measures of variability can range in value from
A) - ∞ to + ∞
B) 0 to + ∞
C) It depends on whether the variability is positive or negative.
D) It depends on the value of the mean for a given distribution. - Answer- B
A researcher records the time (in seconds) that participants arrive late for a scheduled
research study. Assuming these data are normally distributed, which measure of central
tendency is most appropriate to describe these data?
A) mean
B) median
C) mode
D) range - Answer- A
A researcher records the following data for the number of dreams recalled during a
night of sleep for 10 college students: 3, 2, 4, 4, 3, 1, 1, 0, 2, and 0. Is the mean equal to
the median in this example?
A) Yes.
B) No; the median is larger than the mean.
,C) No; the mean is larger than the median.
D)There is not enough information to answer this question. - Answer- A
Which of the following best describes a dependent variable?
A) the sample variable
B) the measured behavior
C) the manipulated variable
D) the population variable - Answer- B
The size of a population is symbolized as ________, whereas the size of a sample is
symbolized as ________.
A) mu; M
B) M;mu
C) n; N
D) N; n - Answer- D
In the stem-and-leaf display, each number to the right of the vertical line is referred to as
a ________; the numbers to the left of the vertical line are called the ________.
A) stem; leaf
B) leaf; stem
C) digit; place
D) place; digit - Answer- B
When would a researcher calculate a population mean?
A) when data are measured for of a portion of individuals from a population
B) when the sample mean is not available
C) when data are measured for all members of a population
D) when it is not possible to measure all data in a population - Answer- C
The median is an appropriate measure of central tendency for
A) data that are positively skewed
B) data that are negatively skewed
C) data that are on an ordinal scale
D) all of the above - Answer- D
What is the percentile point at the 80th percentile in the following distribution?
Frequency Percentile Rank
9-11 100%
6-8 80%
3-5 40%
0-2 20%
A) 2
B) 6
C) 7
D) 8 - Answer- D
,State the problem with this simple frequency distribution.
Intervals Frequency
8-10 4
6-8 7
4-6 3
2-4 6
0-2 9
A) The interval width is too small.
B) The interval width is unequal.
C) The class intervals overlap.
D) The number of intervals is too small. - Answer- C
A researcher wants to determine how many participants will take less than 24 seconds
to complete a cognitive performance task. If he constructs a frequency distribution for
these data, what type of distribution would be most appropriate to answer his question?
A) a simple frequency distribution
B) a relative frequency distribution
C) a cumulative frequency distribution from the bottom up
D) a cumulative frequency distribution from the top down - Answer- C
A researcher selects a sample of 6 males and 11 females. She asks participants to rate
the likelihood they would do female-stereotyped jobs (such as nursing or school
teaching) on a scale from 1 = not likely at all to 5 = very likely. Men indicated that they
would be less likely to do these jobs (M = 2.1) compared with women (M = 4.3). What is
the weighted mean for this entire sample of 17 participants?
A) 2.1
B) 4.3
C) 3.2
D) 3.5 - Answer- D
Which of the following is consistent with the empirical rule?
A) 68% of all scores lie within one standard deviation of the mean.
B) 95% of all scores lie within two standard deviations of the mean.
C) 99.7% of all scores lie within three standard deviations of the mean.
D) all of the above - Answer- D
When SS = 100 and N = 25, the population standard deviation is equal to __
A) 10
B) 2
C) 4
D) There is not enough information to determine the population standard deviation. -
Answer- B
Which of the following is an example of a distribution with NO variability?
, A) scores: 3, 5, 4, 4, 5, and 3
B) scores: 3, 3, 3, 3, 33, and 3
C) scores: 1, 2, 3, 4, 5, and 6
D) scores: 5, 5, 5, 5, 5, and 5 - Answer- D
The range of scores in each interval of a grouped frequency distribution is called the
A) simple frequency
B) interval width
C) real range
D) grouped data - Answer- B
A therapist observes that spouses are more likely to forgive their partners for lying to
them if they find out the truth from their spouse and not a third party. In this example,
the dependent variable is
A) the number of partners
B) the spouse
C) lying
D) forgiveness - Answer- D
Procedures that allow researchers to infer or generalize observations made with
samples to the larger population from which they were selected best describes
A) inferential statistics
B) sample statistics
C) descriptive statistics
D) population parameters - Answer- A
A researcher compares the amount of college debt (in dollars) that undergraduate
students incur up to their four-year degree. College debt is on what scale of
measurement?
A) nominal
B) ordinal
C) interval
D) ratio - Answer- D
Regardless of the number of scores in a distribution, the range only includes ___
score(s) in its calculation.
A) one
B) two
C) at most two
D) the average - Answer- B
Three research methods common to research in the behavioral sciences are
A) experimental, transferable, and correlation
B) experimental, variable, and correlational
C) experimental, operational, and quasi-correlational
D) experimental, quasi-experimental, and correlational - Answer- D
A researcher asks participants to estimate the height (in inches) of a statue that was in
a waiting area. The researcher records the following estimates: 40, 46, 30, 50, and 34. If
the researcher removes the estimate of 40 (say, due to an experimenter error), then the
value of the mean will____ (Hint: Calculate the mean first!)
a) decrease
b) increase
c) remain the same
d) become negative - Answer- C
Researchers measure data in a ________ to learn more about individuals in the larger
_______ of interest.
A) sample; population
B) statistic; inference
C) population; sample
D) inference; statistic - Answer- A
Which of the following is true about the computational formula for variance?
A) The computational formula will always produce the same solution as the definitional
formula (give or take rounding errors).
B) It is a short-cut method for calculating variance when the population or sample size is
large.
C) It is derived mathematically from the definitional formula.
D) all of the above - Answer- D
Measures of variability can range in value from
A) - ∞ to + ∞
B) 0 to + ∞
C) It depends on whether the variability is positive or negative.
D) It depends on the value of the mean for a given distribution. - Answer- B
A researcher records the time (in seconds) that participants arrive late for a scheduled
research study. Assuming these data are normally distributed, which measure of central
tendency is most appropriate to describe these data?
A) mean
B) median
C) mode
D) range - Answer- A
A researcher records the following data for the number of dreams recalled during a
night of sleep for 10 college students: 3, 2, 4, 4, 3, 1, 1, 0, 2, and 0. Is the mean equal to
the median in this example?
A) Yes.
B) No; the median is larger than the mean.
,C) No; the mean is larger than the median.
D)There is not enough information to answer this question. - Answer- A
Which of the following best describes a dependent variable?
A) the sample variable
B) the measured behavior
C) the manipulated variable
D) the population variable - Answer- B
The size of a population is symbolized as ________, whereas the size of a sample is
symbolized as ________.
A) mu; M
B) M;mu
C) n; N
D) N; n - Answer- D
In the stem-and-leaf display, each number to the right of the vertical line is referred to as
a ________; the numbers to the left of the vertical line are called the ________.
A) stem; leaf
B) leaf; stem
C) digit; place
D) place; digit - Answer- B
When would a researcher calculate a population mean?
A) when data are measured for of a portion of individuals from a population
B) when the sample mean is not available
C) when data are measured for all members of a population
D) when it is not possible to measure all data in a population - Answer- C
The median is an appropriate measure of central tendency for
A) data that are positively skewed
B) data that are negatively skewed
C) data that are on an ordinal scale
D) all of the above - Answer- D
What is the percentile point at the 80th percentile in the following distribution?
Frequency Percentile Rank
9-11 100%
6-8 80%
3-5 40%
0-2 20%
A) 2
B) 6
C) 7
D) 8 - Answer- D
,State the problem with this simple frequency distribution.
Intervals Frequency
8-10 4
6-8 7
4-6 3
2-4 6
0-2 9
A) The interval width is too small.
B) The interval width is unequal.
C) The class intervals overlap.
D) The number of intervals is too small. - Answer- C
A researcher wants to determine how many participants will take less than 24 seconds
to complete a cognitive performance task. If he constructs a frequency distribution for
these data, what type of distribution would be most appropriate to answer his question?
A) a simple frequency distribution
B) a relative frequency distribution
C) a cumulative frequency distribution from the bottom up
D) a cumulative frequency distribution from the top down - Answer- C
A researcher selects a sample of 6 males and 11 females. She asks participants to rate
the likelihood they would do female-stereotyped jobs (such as nursing or school
teaching) on a scale from 1 = not likely at all to 5 = very likely. Men indicated that they
would be less likely to do these jobs (M = 2.1) compared with women (M = 4.3). What is
the weighted mean for this entire sample of 17 participants?
A) 2.1
B) 4.3
C) 3.2
D) 3.5 - Answer- D
Which of the following is consistent with the empirical rule?
A) 68% of all scores lie within one standard deviation of the mean.
B) 95% of all scores lie within two standard deviations of the mean.
C) 99.7% of all scores lie within three standard deviations of the mean.
D) all of the above - Answer- D
When SS = 100 and N = 25, the population standard deviation is equal to __
A) 10
B) 2
C) 4
D) There is not enough information to determine the population standard deviation. -
Answer- B
Which of the following is an example of a distribution with NO variability?
, A) scores: 3, 5, 4, 4, 5, and 3
B) scores: 3, 3, 3, 3, 33, and 3
C) scores: 1, 2, 3, 4, 5, and 6
D) scores: 5, 5, 5, 5, 5, and 5 - Answer- D
The range of scores in each interval of a grouped frequency distribution is called the
A) simple frequency
B) interval width
C) real range
D) grouped data - Answer- B
A therapist observes that spouses are more likely to forgive their partners for lying to
them if they find out the truth from their spouse and not a third party. In this example,
the dependent variable is
A) the number of partners
B) the spouse
C) lying
D) forgiveness - Answer- D
Procedures that allow researchers to infer or generalize observations made with
samples to the larger population from which they were selected best describes
A) inferential statistics
B) sample statistics
C) descriptive statistics
D) population parameters - Answer- A
A researcher compares the amount of college debt (in dollars) that undergraduate
students incur up to their four-year degree. College debt is on what scale of
measurement?
A) nominal
B) ordinal
C) interval
D) ratio - Answer- D
Regardless of the number of scores in a distribution, the range only includes ___
score(s) in its calculation.
A) one
B) two
C) at most two
D) the average - Answer- B
Three research methods common to research in the behavioral sciences are
A) experimental, transferable, and correlation
B) experimental, variable, and correlational
C) experimental, operational, and quasi-correlational
D) experimental, quasi-experimental, and correlational - Answer- D
