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 selected from the population.

Question 2

A researcher wants to know the average number of hours college students sleep per night. She surveys 200 students from her university. In this context, what is the parameter?

Accepted Answer

The average number of hours all college students sleep per night.

Question 3

Which of the following is an example of a qualitative (categorical) variable?

Accepted Answer

Type of smartphone (iPhone, Samsung, etc.).

Question 4

Which variable is both quantitative and discrete?

Accepted Answer

Number of students in a classroom

Question 5

A study tracks the blood pressure of 500 adults over 10 years to see if diet affects hypertension. No treatments are assigned. What type of study is this?

Accepted Answer

Observational study

Question 6

Which of the following best describes a simple random sample?

Accepted Answer

A sample where every individual has an equal chance of being selected.

Question 7

Which level of measurement is represented by the variable 'Temperature in Celsius'?

Accepted Answer

Interval

Question 8

A company surveys only its most loyal customers to determine overall satisfaction. What type of bias is most likely present?

Accepted Answer

Sampling bias

Question 9

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

Accepted Answer

Time exercised in a day (in minutes)

Question 10

In a designed experiment, what is the explanatory variable?

Accepted Answer

The variable that is manipulated to observe its effect

Question 11

A survey asks, 'How satisfied are you with our product?' with options: 'Highly satisfied, satisfied, somewhat satisfied, not satisfied.' What type of error may this introduce?

Accepted Answer

Response bias

Question 12

Which formula would you use to calculate the proportion of a sample with a certain characteristic?

Accepted Answer

$$p = \frac{X}{n}$$

Question 13

Which of the following is NOT a source of bias in sampling?

Accepted Answer

Random sampling

Question 14

A researcher uses a random number generator to select 50 students from a list of all students at a university. What type of sampling is this?

Accepted Answer

Simple random sampling

Question 15

Which of the following variables is measured at the ordinal level?

Accepted Answer

Level of education (High School, Bachelor’s, etc.)

Question 16

A magazine surveys its readers and predicts a presidential election result that is very different from the actual outcome. What is the most likely reason?

Accepted Answer

The sample was not representative of the population.

Question 17

Which of the following best describes a parameter?

Accepted Answer

A numerical summary of a population.

Question 18

Which of the following is an example of response bias?

Accepted Answer

Respondents giving socially desirable answers instead of truthful ones.

Question 19

A researcher wants to know if a new teaching method improves test scores. She randomly assigns students to two groups: one uses the new method, the other uses the traditional method. After the semester, she compares their scores. What type of study is this?

Accepted Answer

Designed experiment

Question 20

Which of the following best describes a discrete variable?

Accepted Answer

A variable that can only take on specific, separate values.

Chapter 1: Data Collection – Foundations of Statistics

Study Guide - Practice Questions

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