Question 1

Which of the following best describes a statistic in the context of data collection?

Accepted Answer

A numerical summary based on a sample.

Question 2

A researcher wants to know the average number of hours college students study per week. She surveys 200 students from her university. What is the population in this study?

Accepted Answer

All college students at the university.

Question 3

Which of the following variables is quantitative and continuous?

Accepted Answer

Temperature measured in degrees Celsius.

Question 4

What is the main difference between an observational study and a designed experiment?

Accepted Answer

An observational study does not attempt to influence the value of the response variable.

Question 5

A researcher randomly selects 5 classrooms from a university and surveys all students in those classrooms. What type of sampling method is this?

Accepted Answer

Cluster sampling.

Question 6

Which of the following is an example of sampling bias?

Accepted Answer

A survey conducted only during daytime hours at a university.

Question 7

A variable that allows for classification of individuals based on some attribute or characteristic is called:

Accepted Answer

A qualitative (categorical) variable.

Question 8

Which level of measurement allows for meaningful ratios and has a true zero?

Accepted Answer

Ratio level of measurement.

Question 9

In a double-blind experiment, who is unaware of which treatment is being received?

Accepted Answer

Both the experimental unit (subject) and the researcher.

Question 10

A study records the number of cars that arrive at a McDonald's drive-thru between 12:00 pm and 1:00 pm. What type of variable is being measured?

Accepted Answer

Discrete quantitative variable.

Question 11

Which of the following is NOT a source of nonresponse bias?

Accepted Answer

Randomly assigning treatments in an experiment.

Question 12

A census is defined as:

Accepted Answer

A list of all individuals in a population along with certain characteristics of each individual.

Question 13

Which sampling method involves dividing the population into groups and then randomly selecting individuals from each group?

Accepted Answer

Stratified sampling.

Question 14

Suppose a researcher wants to study the effect of a new medication. She randomly assigns patients to receive either the medication or a placebo. What is the control group in this experiment?

Accepted Answer

The group receiving the placebo.

Question 15

Which of the following best describes a matched-pairs design?

Accepted Answer

Experimental units are paired up so that they are related in some way, and each pair receives both treatments.

Question 16

A researcher uses a systematic sampling method to select every 10th person from a list of 1,000 individuals. What is the sample size if the researcher starts at the 3rd person?

Accepted Answer

$$ n = \frac{1000}{10} = 100 $$

Question 17

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

Accepted Answer

Letter grade earned in a statistics class (A, B, C, D, F).

Question 18

A researcher wants to estimate the proportion of students who own a car at a university. She selects a simple random sample of 250 students. Which formula should she use to calculate the sample proportion $$ \hat{p} $$?

Accepted Answer

$$ \hat{p} = \frac{x}{n} $$

Question 19

Which of the following is a confounding variable in an observational study examining the effect of exercise on heart health?

Accepted Answer

Diet of the participants.

Question 20

In a designed experiment, what is the main purpose of random assignment?

Accepted Answer

To reduce bias and ensure groups are comparable.

Chapter 1: Data Collection – Structured Study Notes for Statistics

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