Question 1

Which of the following statements about the mean and median is TRUE for a right-skewed distribution?

Accepted Answer

The mean is greater than the median.

Question 2

Given the data set: 300, 400, 400, 450, 800, 940, 1050, what is the mode?

Accepted Answer

400

Question 3

A hospital records the following number of patients admitted each day for a week: 30, 35, 40, 45, 50, 100, 105. Which measure of center is MOST affected by the two largest values?

Accepted Answer

Mean

Question 4

Which formula correctly represents the sample mean $\bar{x}$ for a data set with $n$ observations $x_1, x_2, ..., x_n$?

Accepted Answer

$\bar{x} = \frac{\sum_{i=1}^n x_i}{n}$

Question 5

A data set has the following values: 10, 12, 14, 16, 18. What is the median?

Accepted Answer

14

Question 6

Which of the following is NOT a resistant measure of center?

Accepted Answer

Mean

Question 7

A basketball team has player heights (in inches): 67, 72, 76, 76, 84. Calculate the range of the heights.

Accepted Answer

17

Question 8

Which of the following best describes the standard deviation?

Accepted Answer

It measures the average distance of each data point from the mean.

Question 9

Given the sample data: 2, 4, 4, 4, 5, 5, 7, 9, what is the mode?

Accepted Answer

4

Question 10

Which formula is used to calculate the sample variance $s^2$ for a data set with $n$ observations?

Accepted Answer

$s^2 = \frac{\sum (x_i - \bar{x})^2}{n-1}$

Question 11

A data set is left-skewed. Which of the following is most likely TRUE?

Accepted Answer

The mean is less than the median.

Question 12

Which of the following statements about standard deviation is correct?

Accepted Answer

Standard deviation is not resistant to extreme observations.

Question 13

If a data set has two modes, it is called:

Accepted Answer

Bimodal

Question 14

Given the data set: 300, 300, 400, 400, 450, 800, 940, 1050, what is the median?

Accepted Answer

400

Question 15

Which of the following is the correct formula for the sample standard deviation $s$ using the shortcut (faster) method?

Accepted Answer

$s = \sqrt{\frac{\sum x_i^2 - (\sum x_i)^2 / n}{n-1}}$

Question 16

A pharmaceutical company is analyzing the weights (in mg) of pills produced in a batch: 100, 102, 104, 106, 200. Which measure of center would best represent the typical pill weight?

Accepted Answer

Median

Question 17

If all values in a data set are increased by 10, what happens to the standard deviation?

Accepted Answer

It remains unchanged.

Question 18

A sample of five exam scores is: 60, 70, 80, 90, 100. What is the mean?

Accepted Answer

80

Question 19

Which of the following is TRUE about the range as a measure of variation?

Accepted Answer

It is highly sensitive to extreme values.

Question 20

A data set has values: 5, 7, 7, 8, 10, 12, 15. If the value 50 is added, which measure of center will change the most?

Accepted Answer

Mean

Descriptive Measures: Measures of Center and Variation

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