Question 1

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

Accepted Answer

A parameter describes a population, while a statistic describes a sample.

Question 2

A researcher collects the SAT scores of all freshmen at a university. What level of measurement is this data?

Accepted Answer

Interval

Question 3

Which sampling technique involves dividing the population into groups and then randomly selecting all members from some groups?

Accepted Answer

Cluster sampling

Question 4

A study finds that the average number of hours worked per week by a sample of 200 nurses is 38. What is this value an example of?

Accepted Answer

Sample statistic

Question 5

Which of the following is an example of qualitative data?

Accepted Answer

Blood types (A, B, AB, O)

Question 6

A researcher wants to study the effect of a new drug. She randomly assigns subjects to receive either the drug or a placebo. What key element of experimental design is she using?

Accepted Answer

Randomization

Question 7

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

Accepted Answer

Ratio

Question 8

A survey asks respondents to rate their satisfaction on a scale from 1 (very dissatisfied) to 5 (very satisfied). What level of measurement is this?

Accepted Answer

Ordinal

Question 9

Which of the following best describes inferential statistics?

Accepted Answer

Drawing conclusions about a population based on sample data

Question 10

A researcher selects every 10th household from a list of addresses. What sampling technique is being used?

Accepted Answer

Systematic sampling

Question 11

Which of the following is an example of an observational study?

Accepted Answer

Surveying people about their eating habits without intervening

Question 12

A company wants to estimate the average salary of its employees. They randomly select 50 employees from each department. What sampling technique is this?

Accepted Answer

Stratified sampling

Question 13

Which of the following is a confounding variable in an experiment?

Accepted Answer

A variable that influences both the dependent and independent variables

Question 14

In a study, the population consists of all high-tech companies in the U.S. A sample of 100 companies is selected for analysis. Which term best describes the 100 companies?

Accepted Answer

Sample

Question 15

Which of the following is NOT a key element of a well-designed experiment?

Accepted Answer

Convenience

Question 16

A researcher wants to study the effect of exercise on blood pressure. She divides subjects into two groups based on age and then randomly assigns each group to either exercise or no exercise. What experimental design is this?

Accepted Answer

Randomized block design

Question 17

Which formula would you use to calculate the mean of a sample?

Accepted Answer

$$\bar{x} = \frac{\sum x_i}{n}$$

Question 18

A study finds that 60% of sampled households have internet access. Which of the following is a possible inference from this study?

Accepted Answer

About 60% of all households in the population may have internet access.

Question 19

Which of the following is an example of ratio level data?

Accepted Answer

Number of injuries treated in an emergency room

Question 20

A researcher uses a list of random numbers to select students for a survey. What sampling technique is this?

Accepted Answer

Simple random sampling

Elementary Statistics I: Introduction to Statistics – Study Notes

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