Question 1

Which of the following best describes the difference between the population mean and the sample mean in terms of notation?

Accepted Answer

The population mean is denoted by $$\mu$$ and the sample mean is denoted by $$\bar{x}.$$

Question 2

A data set contains the following values: 5, 7, 7, 9, 10. What is the mode of this data set?

Accepted Answer

7

Question 3

Given the data set: 12, 15, 18, 21, 24, what is the median?

Accepted Answer

18

Question 4

Which of the following statements about the range is correct?

Accepted Answer

The range is calculated as the highest value minus the lowest value in the data set.

Question 5

A sample of hotel room rates (in dollars) is: 77, 104, 121, 153, 195, 212, 244, 264. What is the range of this sample?

Accepted Answer

$$264 - 77 = 187$$

Question 6

If a data set has an even number of values, how is the median determined?

Accepted Answer

By averaging the two middle values after arranging the data from lowest to highest.

Question 7

Which formula correctly represents the sample variance $$s^2$$ for a data set with $$n$$ values?

Accepted Answer

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

Question 8

A sample has a variance of $$49. $$What is the standard deviation?

Accepted Answer

$$7$$

Question 9

Which of the following is true about the mode of a data set?

Accepted Answer

It is the value that appears most frequently in the data set.

Question 10

A data set has the following values: 2, 4, 6, 8, 10. What is the mean?

Accepted Answer

$$\frac{2 + 4 + 6 + 8 + 10}{5} = 6$$

Question 11

Which of the following best describes the empirical rule for a normal distribution?

Accepted Answer

About 68% of the data falls within one standard deviation of the mean.

Question 12

If a data set has no value that appears more than once, what can be said about the mode?

Accepted Answer

There is no mode.

Question 13

Which of the following is the correct formula for the population variance $$\$$sigma^2$$?

Accepted Answer

$$\$$sigma^2$$ = \frac{\sum (x - \mu)^2$}{n}$$

Question 14

A sample of 8 hotel room rates has a mean of $$171$$ and the following values: 77, 104, 121, 153, 195, 212, 244, 264. What is the sample variance (rounded to the nearest whole number)?

Accepted Answer

$$4626$$

Question 15

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

Accepted Answer

Range

Question 16

A data set is: 3, 7, 7, 7, 10, 12. What is the median?

Accepted Answer

$$(7 + 7)/2 = 7$$

Question 17

Which of the following statements about standard deviation is correct?

Accepted Answer

Standard deviation is the square root of the variance.

Question 18

In a normal distribution, approximately what percentage of data falls within two standard deviations of the mean?

Accepted Answer

95%

Question 19

A sample of gas prices has a mean of $$4.05$$ and a standard deviation of $$0.15. $$According to the empirical rule, what is the approximate range of prices that would include about 68% of the data?

Accepted Answer

$$4.05 \pm 0.15$$, or from $$3.90 to$$ $$4.20$$

Question 20

Which of the following is a correct statement about using a TI-83/84 calculator for statistics in this course?

Accepted Answer

You should use a TI-83/84 calculator or a reliable app clone, as the course is built around this device.

Chapter 3 Study Guide: Describing, Exploring, and Comparing Data

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