Question 1

The distribution of annual household income in the United States is positively skewed.If the median annual income is about $56,000,this implies that the mean annual household income in the Unites States is

Accepted Answer

A)  smaller. 
B)  larger. 
C)  the same. 
D)  There is not enough information to answer this question.

Question 2

A researcher records 17 scores.What is the median position of these scores?

Accepted Answer

A)  the 9th score in numeric order 
B)  the average of the 9th and 10th scores in numeric order 
C)  the average of the 8th and 9th scores in numeric order 
D)  it's not possible to know this without the raw scores

Question 3

The mean would be used to describe which of the following variables?

Accepted Answer

A)  rankings 
B)  distance traveled in miles 
C)  gender 
D)  model of car

Question 4

The median is an appropriate measure of central tendency for

Accepted Answer

A)  data that are positively skewed. 
B)  data that are negatively skewed. 
C)  data that are on an ordinal scale. 
D)  all of these.

Question 5

The ______ is the sum of all scores (in a sample or population)divided by the number of scores summed.

Accepted Answer

A)  mode 
B)  median 
C)  mean 
D)  range

Question 6

The sample size is in the denominator of the calculation of a sample mean.

Accepted Answer

A) True 
 B)False

Question 7

Which of the following can be used to estimate the median?

Accepted Answer

A)  the 50th percentile of a relative percentage distribution 
B)  the 50th percentile of a cumulative percentage distribution 
C)  the mean 
D)  the mode

Question 8

A researcher records the distance (in feet)traveled in a burning building by firefighters during a rescue attempt.Based on the scale of measurement for these data,describing the mean distance traveled is appropriate.

Accepted Answer

A) True 
 B)False

Question 9

Some,but not all,scores in a distribution are included in the calculation of a mean.

Accepted Answer

A) True 
 B)False

Question 10

A skewed distribution tends to pull the median,but not the mean,toward outliers in the data.

Accepted Answer

A) True 
 B)False

Question 11

A researcher records the following data for the time (in seconds)it takes five rats to cross an electrical grid to obtain reinforcement on the other side: 12,9,13,4,and 12.Is the mean equal to the mode in this example?

Accepted Answer

A)  Yes. 
B)  No; the mode is larger than the mean. 
C)  No; the mean is larger than the mode. 
D)  There is not enough information to answer this question.

Question 12

A researcher records 52 scores.What is the median position of these scores?

Accepted Answer

A)  the 26th score in numeric order 
B)  the average of the 26th and 27th scores in numeric order 
C)  the 27th score in numeric order 
D)  it's not possible to know this without the raw scores

Question 13

A researcher asks participants to estimate the height (in inches)of a statue that is 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

Accepted Answer

A)  decrease. 
B)  increase. 
C)  remain the same. 
D)  become negative.

Question 14

A weighted mean is most appropriate to describe the mean for two or more samples with equal sample sizes.

Accepted Answer

A) True 
 B)False

Question 15

A weighted mean should be used when the "weights" are not equal.

Accepted Answer

A) True 
 B)False

Question 16

The sum of the differences of scores from their mean is zero.

Accepted Answer

A) True 
 B)False

Question 17

A researcher measures the mean time (in seconds)it takes two groups of children to complete an activity task.She finds that Group A (M = 22 s)completed the task more quickly than Group B (M = 36 s).She then computes a weighted mean for both groups combined and calculates a weighted mean equal to 26.Based on the information provided,which group had a larger sample size?

Accepted Answer

A)  Group A. 
B)  Group B. 
C)  The sample size is equal in both groups. 
D)  It is not possible to know this without knowing the sample size for each group.

Question 18

The population mean is used to estimate the value of a sample mean.

Accepted Answer

A) True 
 B)False

Question 19

The ______ is the value that occurs most often or at the highest frequency in a distribution.

Accepted Answer

A)  mean 
B)  median 
C)  mode 
D)  range

Question 20

A researcher asks participants to estimate the calories they consume in a meal.The researcher records the following estimates: 450,426,310,500,and 220.If the researcher removes the estimate of 220 (perhaps because the participant drops out of the study),then the value of the mean will

Accepted Answer

A)  decrease. 
B)  increase. 
C)  remain the same. 
D)  become negative.

Exam 3: Summarizing Data: Central Tendency

The distribution of annual household income in the United States is positively skewed.If the median annual income is about $56,000,this implies that the mean annual household income in the Unites States is

A researcher records 17 scores.What is the median position of these scores?

The mean would be used to describe which of the following variables?

The median is an appropriate measure of central tendency for

The ______ is the sum of all scores (in a sample or population) divided by the number of scores summed.

The sample size is in the denominator of the calculation of a sample mean.

Which of the following can be used to estimate the median?

A researcher records the distance (in feet)traveled in a burning building by firefighters during a rescue attempt.Based on the scale of measurement for these data,describing the mean distance traveled is appropriate.

Some,but not all,scores in a distribution are included in the calculation of a mean.

A skewed distribution tends to pull the median,but not the mean,toward outliers in the data.

A researcher records the following data for the time (in seconds) it takes five rats to cross an electrical grid to obtain reinforcement on the other side: 12,9,13,4,and 12.Is the mean equal to the mode in this example?

A researcher records 52 scores.What is the median position of these scores?

A researcher asks participants to estimate the height (in inches) of a statue that is 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

A weighted mean is most appropriate to describe the mean for two or more samples with equal sample sizes.

A weighted mean should be used when the "weights" are not equal.

The sum of the differences of scores from their mean is zero.

The population mean is used to estimate the value of a sample mean.

The ______ is the value that occurs most often or at the highest frequency in a distribution.

A researcher asks participants to estimate the calories they consume in a meal.The researcher records the following estimates: 450,426,310,500,and 220.If the researcher removes the estimate of 220 (perhaps because the participant drops out of the study) ,then the value of the mean will