Q: A student’s grades are: A (4 credits), B (3 credits), C (2 credits), and D (1 credit). If the student earned grades of A, B, and C in courses worth 3, 4, and 3 credits respectively, what is the weighted mean (GPA)?

$$\frac{(4 \times 3) + (3 \times 4) + (2 \times 3)}{3 + 4 + 3}$$

Question 1

Which of the following best describes the mean of a data set?

Accepted Answer

The sum of all data entries divided by the number of entries.

Question 2

Given the data set: 12, 15, 15, 18, 20, what is the median?

Accepted Answer

$$15$$

Question 3

A sample of exam scores is: 70, 85, 90, 95, 100. If the student who scored 100 was absent and not included, what is the new mean?

Accepted Answer

$$85$$

Question 4

Which measure of central tendency is most affected by an outlier?

Accepted Answer

Mean

Question 5

A student’s grades are: A (4 credits), B (3 credits), C (2 credits), and D (1 credit). If the student earned grades of A, B, and C in courses worth 3, 4, and 3 credits respectively, what is the weighted mean (GPA)?

Accepted Answer

$$\frac{(4 	imes 3) + (3 	imes 4) + (2 	imes 3)}{3 + 4 + 3}$$

Question 6

Which of the following distributions is described as having a tail that elongates more to the right?

Accepted Answer

Skewed right distribution

Question 7

If a data set is: 5, 7, 7, 8, 10, 12, 15, which value is the mode?

Accepted Answer

$$7$$

Question 8

A frequency distribution has class midpoints $$x$$ and frequencies $$f. $$Which formula estimates the mean of the grouped data?

Accepted Answer

$$\bar{x} = \frac{\sum x f}{\sum f}$$

Question 9

Which measure of central tendency is most appropriate for categorical data, such as political party affiliation?

Accepted Answer

Mode

Question 10

A data set is described as symmetric. Which of the following is true about its mean and median?

Accepted Answer

The mean and median are approximately equal.

Question 11

A hospital administrator wants to summarize the typical length of stay for patients. The data are highly skewed right due to a few patients with very long stays. Which measure should be used?

Accepted Answer

Median

Question 12

Which of the following best describes a uniform distribution?

Accepted Answer

All entries have equal or approximately equal frequencies.

Question 13

A data set contains the values: 2, 4, 4, 6, 8, 10, 100. Which measure of central tendency is most affected by the value 100?

Accepted Answer

Mean

Question 14

If a data set has two entries that occur with the same greatest frequency, what is the mode called?

Accepted Answer

Bimodal

Question 15

A teacher wants to estimate the mean test score for a large class using grouped data. Which of the following is the correct approach?

Accepted Answer

Use the midpoints of each class and their frequencies in the formula $$\bar{x} = \frac{\sum x f}{\sum f}.$$

Question 16

Which of the following is NOT a measure of central tendency?

Accepted Answer

Range

Question 17

A data set is skewed left. Which of the following is true?

Accepted Answer

The mean is to the left of the median.

Question 18

Which of the following is a disadvantage of using the mean as a measure of central tendency?

Accepted Answer

It is greatly affected by outliers.

Question 19

A researcher collects the following data on daily step counts: 5000, 7000, 8000, 10000, 12000. What is the mean number of steps?

Accepted Answer

$$8400$$

Question 20

Which of the following best describes the median?

Accepted Answer

The value that divides the ordered data set into two equal parts.

Measures of Central Tendency in Descriptive Statistics

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