Question 1

Which of the following best describes a parameter in statistics?

Accepted Answer

A numerical summary that describes a characteristic of a population.

Question 2

A researcher collects the heights (in inches) of 100 randomly selected adult males in a city. Which of the following best describes the variable 'height'?

Accepted Answer

Quantitative variable

Question 3

Given a histogram of test scores that is skewed to the right, which of the following is most likely true?

Accepted Answer

The mean is greater than the median.

Question 4

A simple random sample is best described as:

Accepted Answer

A sample in which each member of the population has an equal chance of being selected.

Question 5

Suppose the mean score on a statistics exam is 75 with a standard deviation of 8. What is the z-score for a student who scored 91?

Accepted Answer

$$z = \frac{91 - 75}{8} = 2$$

Question 6

Which of the following is NOT a property of the standard deviation?

Accepted Answer

It is always greater than the range.

Question 7

A pie chart is most appropriate for displaying which type of data?

Accepted Answer

Categorical data

Question 8

If a set of test scores has a mean of 80 and a standard deviation of 10, what is the z-score for a score of 70?

Accepted Answer

$$z = \frac{70 - 80}{10} = -1$$

Question 9

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 10

A frequency table is used to:

Accepted Answer

Display the distribution of a categorical variable.

Question 11

A researcher wants to estimate the average cholesterol level of adults in a city. She randomly selects 200 adults and calculates the mean cholesterol level. The mean calculated from the 200 adults is:

Accepted Answer

A statistic

Question 12

Which of the following is an example of an observational study?

Accepted Answer

A researcher records the number of hours students study without intervening.

Question 13

If the heights of adult women are approximately normally distributed with a mean of 65 inches and a standard deviation of 3 inches, what percentage of women are expected to be between 62 and 68 inches tall?

Accepted Answer

About 68%

Question 14

Which of the following best describes a skewed distribution?

Accepted Answer

A distribution with a long tail on one side.

Question 15

A set of exam scores has a mean of 70 and a standard deviation of 5. If a student’s z-score is 2, what was their exam score?

Accepted Answer

$$x = 70 + 2 	imes 5 = 80$$

Question 16

Which of the following is a correct interpretation of the 90th percentile in a data set?

Accepted Answer

90% of the data values are below this value.

Question 17

Which of the following is a valid reason to use a bar graph instead of a pie chart?

Accepted Answer

Bar graphs make it easier to compare the sizes of different categories.

Question 18

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

Accepted Answer

4

Question 19

Which of the following best describes the margin of error in a survey?

Accepted Answer

An estimate of how much the sample statistic is likely to differ from the population parameter.

Question 20

A researcher wants to compare the average test scores of students in two different schools. Which type of study is this?

Accepted Answer

Observational study

Foundations of Statistics: Key Concepts, Data Analysis, and the Normal Distribution

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