Question 1

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

Accepted Answer

A) gender 
B) ethnicity 
C) rankings 
D) brand name

Question 2

The population mean is symbolized as ________,whereas the sample mean is symbolized as ________.

Accepted Answer

A) $\mu$;M 
B) M;$\mu$ 
C) n;N 
D) N;n

Question 3

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

Accepted Answer

A) True 
 B)False

Question 4

A professor grades 120 research papers and reports that the average score was an 80%.What do we know about the sum of the differences of these 120 scores from their mean of 80%?

Accepted Answer

A) The sum of the differences is minimal. 
B) The sum of the differences is 80%,the same as the mean. 
C) The sum of the differences is equal to zero. 
D) It is impossible to know without knowing each of the 120 scores.

Question 5

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 6

The mode is an appropriate measure of central tendency for

Accepted Answer

A) data that are bimodal 
B) use with other measures of central tendency 
C) data that are on a nominal scale 
D) all of the above

Question 7

Adding the same constant to each score in a distribution (or subtracting the same constant from it)will

Accepted Answer

A) cause the mean to change by that constant 
B) not change the mean at all because the same constant was added to or subtracted from each score

Question 8

A researcher records the following scores: 5,3,7,6,2,8,0,and 1.In terms of these data,the sum of the squared differences of scores from their mean is

Accepted Answer

A) 0 
B) 8 
C) 32 
D) 60

Question 9

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 seconds)completed the task more quickly than Group B (M = 36 seconds).She then computes a weighted mean for both groups combined and calculates = 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 10

Which of the following is NOT a characteristic of the mean?

Accepted Answer

A) Add a score above the mean and the mean will increase. 
B) Add a score below the mean and the mean will decrease. 
C) Delete a score below the mean and the mean will increase. 
D) Delete a score above the mean and the mean will increase.

Question 11

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

Accepted Answer

A) True 
 B)False

Question 12

Three measures of central tendency are the mean,median,and range.

Accepted Answer

A) True 
 B)False

Question 13

Adding a new score to a set of scores will change the mean,even when the score that is added is equal to the mean.

Accepted Answer

A) True 
 B)False

Question 14

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

Accepted Answer

A) True 
 B)False

Question 15

A weighted mean weighs each sample mean by the sample size for each sample in the formula.

Accepted Answer

A) True 
 B)False

Question 16

The formula for a population mean and a sample mean are defined using the same notation.

Accepted Answer

A) True 
 B)False

Question 17

A researcher reports,"the average patron (n = 22)in a local bar consumed more than twice the number of drinks (per day)on weekends (M = 5.4 drinks)compared to weekdays (M = 2.3 drinks)." Although not stated directly,how do we know that the patrons in this study constitute a sample,and not a population of patrons at this local bar?

Accepted Answer

A) We can't know for sure because this was not stated directly. 
B) The notation for a sample mean was used. 
C) The notation for sample size was used. 
D) both B and C

Question 18

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 19

Multiplying or dividing each score in a distribution by the same constant will

Accepted Answer

A) cause the mean to change by that constant 
B) not change the mean at all because each score was multiplied or divided by the same constant

Question 20

If a portion of people from a population are asked to complete an assessment,then the average score among that group of people would be considered a

Accepted Answer

A) sample mean 
B) population mean 
C) median split 
D) modal mean

Exam 3: Summarizing Data: Central Tendency

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

The population mean is symbolized as ,whereas the sample mean is symbolized as .

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

A professor grades 120 research papers and reports that the average score was an 80%.What do we know about the sum of the differences of these 120 scores from their mean of 80%?

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

The mode is an appropriate measure of central tendency for

Adding the same constant to each score in a distribution (or subtracting the same constant from it) will

A researcher records the following scores: 5,3,7,6,2,8,0,and 1.In terms of these data,the sum of the squared differences of scores from their mean is

Which of the following is NOT a characteristic of the mean?

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

Three measures of central tendency are the mean,median,and range.

Adding a new score to a set of scores will change the mean,even when the score that is added is equal to the mean.

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

A weighted mean weighs each sample mean by the sample size for each sample in the formula.

The formula for a population mean and a sample mean are defined using the same notation.

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?

Multiplying or dividing each score in a distribution by the same constant will

If a portion of people from a population are asked to complete an assessment,then the average score among that group of people would be considered a