Quiz #3 - Chapter 3 - Central Tendency

Question 1

Consider the following set of depression scores: 7,10,10,12,31,38

What is the sample mean?

What is the sample median?

What is the sample mode?

Answer 1

What is the sample mean? 18

What is the sample median? 11

What is the sample mode? 10

Question 2

Considering the frequency distribution below:

Response:
Strongly Agree - 20
Agree - 10
Neither agree not disagree - 25
Disagree - 30
Strongly disagree - 15

What response category corresponds to the mode?

Answer 2

Disagree

Question 3

Considering the frequency distribution below:

Response:
Strongly Agree - 20
Agree - 10
Neither agree not disagree - 25
Disagree - 30
Strongly disagree - 15

What response category corresponds to the median?

Answer 3

Neither agree nor disagree

Question 4

A researcher wants to use a measure of central tendency to summarize the political party breakdown of his sample. Which measures of central tendency can be computed for this variable? Note that the question is NOT asking which one you should use, but which one you COULD use as a REASONABLE measure. Check ALL that apply.

A: Mean
B: Median
C: Mode

Answer 4

C: Mode

Question 5

A researcher is studying the distribution of number of pets per family and she wants to report the central tendency for this distribution. Which measures of central tendency can be computed for this variable? Note that the question is NOT asking which one you should use, but which one you COULD use as a REASONABLE measure. Check all that apply.

A: Mean
B: Median
C: Mode

Answer 5

A: Mean, B: Median, AND C: Mode - you can use all of them

Question 6

A researcher is studying the distribution of academic letter grades (i.e., A, B, C, and D) in a college and she wants to report the central tendency for the academic letter grades. Which measures of central tendency can be computed for this variable? Note that the question is NOT asking which one you should use, but which one you COULD use as a REASONABLE measure. Check all that apply.

A: Mean
B: Mode
C: Median

Answer 6

B: Mode AND C: Median

Question 7

With what types of variables can the mean be used? Check all that apply.

A: Numeric
B: Nominal
C: Ordinal

Answer 7

A: Numeric

Question 8

With what types of variables can the mode be used? Check all that apply.

A: Numeric
B: Ordinal
C: Nominal

Answer 8

A: Numeric, B: Ordinal, AND C: Nominal - yo can use all of them

Question 9

A researcher obtains the mean, median, and mode for his data. The mean, median, and mode all equal 10. Based on these descriptive statistics, how is this data likely to be distributed?

A: Positively skewed
B: Symmetric distribution
C: Negatively skewed

Answer 9

B: Symmetric distribution

Question 10

A researcher obtains the mean, median, and mode for his data. The mean is 10, median is 12, and mode is 20. Based on these descriptive statistics, how is this data likely to be distributed?

A: Symmetric distribution
B: Negatively skewed
C: Positively skewed

Answer 10

B: Negatively skewed

Question 11

A researcher’s sample mean equals 20. If the true mean in the full population is 18, what is the sampling error?

Answer 11

2

Question 12

Which best describes the sample mean?

A: The sample mean is the number of data in the population divided by the sum of the data.

B: The sample mean is the number of data in the sample divided by the sum of the data.

C: The sample mean is the sum of the data divided by the number of data in the population.

D: The sample mean is the sum of the data divided by the number of data in the sample.

Answer 12

D: The sample mean is the sum of the data divided by the number of data in the sample.

Question 13

True or False: Because we can’t always calculate the parameter of a statistic, we often need to calculate the estimate of a statistic instead.

Answer 13

True

Question 14

A sample mean is a/an ______.
A population mean is a/an ________.

A: Measure of variability/measure of central tendency
B: Estimate/parameter
C: Parameter/estimate
D: Measure of central tendency/measure of variability

Answer 14

B: Estimate/parameter

Question 15

For which of the following data sets is the mode equal to the median?

A: 2, 3, 4, 5, 5, 6
B: 1, 19, 20, 21, 40, 40
C: 1, 1, 1, 3, 3, 3
D: 3, 4, 4, 4, 5, 10

Answer 15

D: 3, 4, 4, 4, 5, 10

Question 16

When sample size increases:

A: Sampling error generally increases
B: Sampling error generally is biased
C: Sampling error generally decreases
D: Sampling error generally stays the same

Answer 16

C: Sampling error generally decreases

Question 17

In a negatively skewed distribution, we would expect…

A: The mean, median, and mode to be roughly equal

B: The mean to be larger than the median and the median to be larger than the mode

C: The mean to be smaller than the median and the median to be smaller than the mode

Answer 17

C: The mean to be smaller than the median and the median to be smaller than the mode

Question 18

True or false: Sampling error can be either positive or negative.

Answer 18

True

Question 19

A UCLA professor is interested in studying the height of college students in California. Somehow, she knows that the true population mean is 67 inches. The mean height of students in her Psych 100A class is 68 inches. She then goes to USC and finds the mean height of their 100A class. Which of the following is true about the sampling error of the USC 100A class?

A: It could be positive or negative

B: It will be negative, because it must average out to 67 inches

C: It will be positive, because all sampling errors will be positive

D: It will also be positive, like the UCLA class

Answer 19

A: It could be positive or negative

Question 20

Please see the corresponding Google Doc for additional questions with graphs and images

Answer 20

Please see the corresponding Google Doc for additional questions with graphs and images