Q: Suppose you convert 73% of 125 people to a count. What is the correct calculation and rounded answer?

$$73 \div 100 \times 125 = 91.25$$, rounded up to 92

Question 1

Which of the following best describes the difference between a parameter and a statistic?

Accepted Answer

A parameter is a numerical summary of a population, while a statistic is a numerical summary of a sample.

Question 2

A researcher wants to estimate the average GPA of all students who transferred from SMC to UCLA. She collects data from 30 randomly selected students out of 500. In this context, what is the population?

Accepted Answer

All students who transferred from SMC to UCLA.

Question 3

Which of the following variables is qualitative?

Accepted Answer

The student ID number assigned to each student.

Question 4

A study records the heights of tables in a classroom, which can take any value between 2 and 3 feet. What type of variable is 'height' in this context?

Accepted Answer

Continuous quantitative variable

Question 5

Which level of measurement is represented by the following data: 'Freshman', 'Sophomore', 'Junior', 'Senior'?

Accepted Answer

Ordinal

Question 6

A researcher divides a population into groups based on political party (Democrat, Republican, Independent) and then randomly selects individuals from each group. What type of sampling method is this?

Accepted Answer

Stratified sampling

Question 7

Which of the following is an example of a systematic sampling method?

Accepted Answer

Selecting every 10th person who enters a store.

Question 8

A TV station asks its viewers to call in and vote for their favorite show. What type of bias is most likely present in this survey?

Accepted Answer

Voluntary response bias

Question 9

Which of the following best describes a double-blind experiment?

Accepted Answer

Both the subjects and the administrators do not know which treatment is given.

Question 10

A researcher wants to study the effect of a new medication on blood pressure. She randomly assigns patients to receive either the medication or a placebo and measures their blood pressure after 4 weeks. What type of study is this?

Accepted Answer

Experiment

Question 11

Which of the following is an example of a confounding variable in a study examining the effect of exercise on weight loss?

Accepted Answer

The amount of water consumed by participants.

Question 12

Suppose you convert 73% of 125 people to a count. What is the correct calculation and rounded answer?

Accepted Answer

$$73 \div 100 	imes 125 = 91.25$$, rounded up to 92

Question 13

Which of the following is NOT a type of non-sampling error?

Accepted Answer

Sampling error

Question 14

A researcher wants to study the average commute time for all employees at a large company. She randomly selects 5 departments and surveys all employees in those departments. What sampling method is she using?

Accepted Answer

Cluster sampling

Question 15

Which of the following best describes the ratio level of measurement?

Accepted Answer

Data can be ranked, and differences and ratios are meaningful; there is a true zero.

Question 16

A survey is conducted among only honor society students at a university to estimate the average GPA of all students. What type of bias is most likely present?

Accepted Answer

Sampling bias due to undercoverage

Question 17

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

Accepted Answer

The number of cars owned by a family

Question 18

A researcher uses a convenience sample to collect data. Which of the following is a likely consequence?

Accepted Answer

The sample may not be representative of the population.

Question 19

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

Accepted Answer

To extend results from a sample to a population and make predictions.

Question 20

A researcher wants to select a simple random sample of 50 students from a population of 500. Which of the following methods would achieve this?

Accepted Answer

Assign a number to each student and use a random number generator to select 50 students.

Chapter 1: Data Collection – Foundations of Statistics

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