Question 1

Which of the following best describes the difference between a population and a sample in statistics?

Accepted Answer

A population is the overall collection of all individuals or items, while a sample is a subset of the population.

Question 2

Which level of measurement allows for the calculation of differences between data entries, but not for the calculation of ratios?

Accepted Answer

Interval

Question 3

A researcher wants to study the effect of a new drug. She randomly assigns patients to receive either the drug or a placebo and compares the outcomes. What type of statistical study design is this?

Accepted Answer

Experiment

Question 4

Which sampling method involves dividing the population into naturally occurring subgroups and then randomly selecting entire subgroups for the sample?

Accepted Answer

Cluster Sampling

Question 5

Given the following data set: 10, 12, 14, 16, 18, what is the mean?

Accepted Answer

$$ \frac{10+12+14+16+18}{5} = 14 $$

Question 6

A frequency distribution table is constructed for a data set using five classes. If the lowest value is 101 and the highest is 160, what is the class width?

Accepted Answer

$$ \frac{160 - 101 + 1}{5} = 12 $$

Question 7

Which of the following is NOT a characteristic of the normal distribution according to the Empirical Rule (68-95-99.7 Rule)?

Accepted Answer

About 50% of the data lie within one standard deviation of the mean.

Question 8

If a data set has a mean of 50 and a standard deviation of 5, what is the z-score for a value of 60?

Accepted Answer

$$ z = \frac{60 - 50}{5} = 2 $$

Question 9

Which of the following best describes the coefficient of variation (CV) for a data set?

Accepted Answer

The standard deviation expressed as a percentage of the mean.

Question 10

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

Accepted Answer

4

Question 11

Which of the following is the correct formula for the sample variance $$ s^2$ $$?

Accepted Answer

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

Question 12

A stem-and-leaf plot is most useful for which of the following purposes?

Accepted Answer

Sorting data for frequency analysis.

Question 13

If a data set has the values 3, 7, 8, 12, 15, what is the median?

Accepted Answer

8

Question 14

Which of the following is a correct interpretation of a z-score of -1.5?

Accepted Answer

The value is 1.5 standard deviations below the mean.

Question 15

A frequency histogram is used to:

Accepted Answer

Represent the frequency distribution of a data set using bars.

Question 16

Which of the following is an example of a quantitative variable?

Accepted Answer

Number of siblings

Question 17

In a systematic sample, how are the members of the population selected?

Accepted Answer

At regular intervals from a starting number.

Question 18

If the range of a data set is 20 and the minimum value is 5, what is the maximum value?

Accepted Answer

25

Question 19

Which of the following best describes the first quartile (Q1) in a data set?

Accepted Answer

The value below which 25% of the data fall.

Question 20

A data set has a mean of 100 and a standard deviation of 20. What is the coefficient of variation (CV) for this data set?

Accepted Answer

$$ CV = \frac{20}{100} 	imes 100\% = 20\% $$

Statistics Fundamentals: Chapters 1 & 2 Review

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드