Question 1

The mean,median,and mode are all the same value in a perfect normal distribution.

Accepted Answer

A) True 
 B)False

Question 2

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 3

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

Accepted Answer

A) True 
 B)False

Question 4

A researcher selects a sample of 6 professors,6 students,and 6 administrators at a local school and has them rate the effectiveness of an innovative new teaching style.In this example,is it possible that the weighted mean ratings will equal the arithmetic mean for the entire sample of 18 participants?

Accepted Answer

A) No,the weighted mean is never exactly equal to the arithmetic mean. 
B) Yes,because there are an even number of participants in each sample. 
C) Yes,because the sample sizes are equal in this example. 
D) It is not possible to know this without knowing the mean for each sample.

Question 5

The mean is an appropriate measure of central tendency for

Accepted Answer

A) data that are normally distributed 
B) data that are on an interval or ratio scale 
C) data in which the mean,median,and mode are equal 
D) all of the above

Question 6

The weighted mean can be computed to determine the mean for samples with unequal sample sizes.

Accepted Answer

A) True 
 B)False

Question 7

Which of the following will decrease the value of the mean?

Accepted Answer

A) deleting a score below the mean 
B) adding a score below the mean 
C) adding a score exactly equal to the mean 
D) none of the above

Question 8

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 9

The median cannot be at the center of a distribution if the mean is also at the center of the distribution.

Accepted Answer

A) True 
 B)False

Question 10

A researcher asks adult participants to rank their top five favorite songs from their childhood.Based on the scale of measurement described,which measure of central tendency is most appropriate to describe these data?

Accepted Answer

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

Question 11

The numerator of the sample mean and the population mean is the same.

Accepted Answer

A) True 
 B)False

Question 12

The mathematical term ∑x is the numerator for

Accepted Answer

A) the population mean 
B) the sample mean 
C) both A and B 
D) None;this term is not in the numerator for any calculation.

Question 13

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 14

A researcher records the following data for the number of times an interviewer is interrupted during a series of interviews: 0,0,3,2,5,3,0,8,0,2,1,and 1.Is the mode equal to the median in this example?

Accepted Answer

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

Question 15

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 16

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?

Accepted Answer

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.

Question 17

When would a researcher calculate a population mean?

Accepted Answer

A) when data are measured for of a portion of individuals from a population 
B) when the sample mean it 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

Question 18

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 19

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 20

Which of the following is not a symbol used with samples:

Accepted Answer

A) x 
B) M 
C) $\mu$ 
D) n

Exam 3: Summarizing Data: Central Tendency

The mean,median,and mode are all the same value in a perfect normal distribution.

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

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

The mean is an appropriate measure of central tendency for

The weighted mean can be computed to determine the mean for samples with unequal sample sizes.

Which of the following will decrease the value of the mean?

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?

The median cannot be at the center of a distribution if the mean is also at the center of the distribution.

A researcher asks adult participants to rank their top five favorite songs from their childhood.Based on the scale of measurement described,which measure of central tendency is most appropriate to describe these data?

The numerator of the sample mean and the population mean is the same.

The mathematical term ∑x is the numerator for

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

A researcher records the following data for the number of times an interviewer is interrupted during a series of interviews: 0,0,3,2,5,3,0,8,0,2,1,and 1.Is the mode equal to the median in this example?

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

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?

When would a researcher calculate a population mean?

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

Which of the following is not a symbol used with samples: