Question 1

Which measure of central tendency is most appropriate to use when a data set contains one or more extreme outliers?

Accepted Answer

Median

Question 2

A researcher collects the following scores: 2, 3, 3, 4, 5, 7, 10. What is the mean of this data set?

$M = \frac{\sum X}{N}$

Accepted Answer

4.86

Question 3

Which of the following best describes a bimodal distribution?

Accepted Answer

A distribution with two most common scores

Question 4

Given the scores: 8, 12, 15, 15, 18, 20, 22, what is the median?

Accepted Answer

15

Question 5

A teacher wants to summarize the most frequent test score in her class. Which measure of central tendency should she use?

Accepted Answer

Mode

Question 6

Which formula correctly represents the calculation of the range?

Accepted Answer

$range = X_{highest} - X_{lowest}$

Question 7

If a data set is nominal (categorical), which measure of central tendency is most appropriate?

Accepted Answer

Mode

Question 8

A sample of exam scores is: 70, 75, 80, 85, 90. Calculate the variance using the formula:

$SD^2 = \frac{\sum (X - M)^2}{N}$

Accepted Answer

50.0

Question 9

Which of the following is NOT a measure of variability?

Accepted Answer

Mode

Question 10

What is the standard deviation if the variance of a data set is 25?

$SD = \sqrt{Variance}$

Accepted Answer

5

Question 11

Which measure of central tendency is most affected by extreme values (outliers)?

Accepted Answer

Mean

Question 12

A data set has the following values: 3, 5, 7, 7, 8, 10, 12. What is the interquartile range (IQR)?

Accepted Answer

3

Question 13

Which of the following is the correct formula for calculating the mean?

Accepted Answer

$M = \frac{\sum X}{N}$

Question 14

A distribution of test scores is highly skewed to the right. Which measure of central tendency would best represent the center of this data set?

Accepted Answer

Median

Question 15

Which of the following steps is NOT part of calculating the variance?

Accepted Answer

Multiply all scores together

Question 16

A researcher finds that the most common age in a sample is 22, but there are also many people aged 30 and 40. What type of distribution is this most likely?

Accepted Answer

Multimodal

Question 17

If the scores in a data set are: 4, 8, 8, 10, 12, what is the mode?

Accepted Answer

8

Question 18

Which of the following best describes the standard deviation?

Accepted Answer

The typical amount that scores vary from the sample mean

Question 19

A data set has a mean of 50 and a standard deviation of 5. What is the variance?

Accepted Answer

25

Question 20

Which measure of variability is calculated as the difference between the 75th and 25th percentiles?

Accepted Answer

Interquartile range

Central Tendency and Variability: Key Concepts and Calculations

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