Question 1

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

Accepted Answer

A population includes all individuals of interest, while a sample is a subset of the population.

Question 2

A researcher collects data on the number of books read by students in a month. What type of variable is this?

Accepted Answer

Quantitative, discrete variable

Question 3

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

Accepted Answer

Temperature in Celsius

Question 4

A survey asks respondents to rate their satisfaction as 'Very Satisfied', 'Satisfied', 'Neutral', or 'Dissatisfied'. What is the level of measurement for this variable?

Accepted Answer

Ordinal

Question 5

Which of the following best describes a simple random sample?

Accepted Answer

A sample where every possible sample of a given size has an equally likely chance of being chosen.

Question 6

A study tracks the blood pressure of 200 randomly selected adults to determine the effect of a new medication. The average decrease in blood pressure is 12 points. In this context, what is the statistic?

Accepted Answer

The average decrease of 12 points

Question 7

Which of the following is a source of response bias in a survey?

Accepted Answer

Respondents giving answers they think are socially acceptable

Question 8

A bar graph is misleading if:

Accepted Answer

The vertical axis does not start at zero.

Question 9

Given the following histogram shapes, which one is described as 'skewed right'?

Accepted Answer

A histogram with a longer tail on the right side

Question 10

In the context of educational attainment data, why is it better to compare relative frequencies rather than frequencies between 1990 and 2021?

Accepted Answer

Relative frequencies account for different population sizes, making comparisons fair.

Question 11

A pie chart is most appropriate when you want to:

Accepted Answer

Show how each category forms a part of the whole

Question 12

Which of the following is an example of nonresponse bias?

Accepted Answer

People who are selected for a survey choose not to respond, and their opinions differ from those who do respond.

Question 13

A frequency distribution table for fines in New York City shows the following class: $$200-224.99$$ with a frequency of 13. What is the relative frequency for this class if the total number of fines is 50?

Accepted Answer

$$0.26$$

Question 14

Which of the following best describes a time-series plot?

Accepted Answer

A plot that shows how a variable changes over time, with time on the horizontal axis

Question 15

A researcher wants to determine if a new teaching method improves test scores. She randomly assigns students to two groups, one using the new method and one using the traditional method. What type of study is this?

Accepted Answer

Designed experiment

Question 16

Which of the following is a potential source of sampling bias?

Accepted Answer

Surveying only people who have internet access for an online poll

Question 17

If a histogram of exam scores is bell-shaped and symmetric, what can you infer about the distribution of scores?

Accepted Answer

Most scores are around the center, with fewer at the extremes

Question 18

Which of the following is an example of a variable measured at the ratio level?

Accepted Answer

Number of students in a classroom

Question 19

A misleading graph is created by using bars of unequal width. What is the main problem with this approach?

Accepted Answer

It distorts the visual impression of the data, making some categories appear more important than they are.

Question 20

Which of the following best describes the purpose of inferential statistics?

Accepted Answer

To use sample data to make generalizations about a population and assess the reliability of those generalizations

STA2023 Statistical Methods I: Data Collection and Data Organization

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