Question 1

A pharmaceutical company wants to test a new drug. They divide patients into two groups based on age (under 50 and 50 or older), then randomly assign treatments within each group. What type of experimental design is this?

Accepted Answer

Randomized Block Design

Question 2

Which of the following best describes a parameter?

Accepted Answer

A numerical measurement describing some characteristic of a population

Question 3

A researcher collects the heights of all students in a university. What is the level of measurement for this data?

Accepted Answer

Ratio

Question 4

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

Accepted Answer

Ordinal

Question 5

A study finds a statistically significant difference in test scores between two teaching methods, with a $$p-$$value of $$0.03. $$However, the average difference in scores is only $$0.5$$ points out of $$100. $$What is the best interpretation?

Accepted Answer

The result is statistically significant but may not be practically significant.

Question 6

Which of the following is an example of a voluntary response sample?

Accepted Answer

Surveying people who choose to call in to a radio show

Question 7

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

Accepted Answer

Cluster sampling

Question 8

Which of the following statements is TRUE regarding correlation and causation?

Accepted Answer

Correlation does not imply causation.

Question 9

A study collects data on the number of car accidents in a city each month for the past 10 years. What type of observational study is this?

Accepted Answer

Retrospective (case-control) study

Question 10

Which of the following is an example of continuous data?

Accepted Answer

The time it takes to run a marathon

Question 11

A researcher wants to study the effect of a new fertilizer on plant growth. She randomly assigns 100 plants to receive either the new fertilizer or a standard fertilizer, and neither she nor the person measuring the plants knows which fertilizer each plant received. What is this an example of?

Accepted Answer

Double-blind experiment

Question 12

Which of the following is a nonsampling error?

Accepted Answer

Recording data incorrectly due to a typo

Question 13

A researcher wants to select a sample of 200 people from a list of 10,000. She randomly chooses a starting point and then selects every 50th person on the list. What sampling method is this?

Accepted Answer

Systematic sampling

Question 14

Which of the following best describes a census?

Accepted Answer

A collection of data from every member of the population

Question 15

A study measures the temperature in Celsius of different cities. What is the level of measurement for this data?

Accepted Answer

Interval

Question 16

In a study, the sample mean is $$\bar{x} = 52$$ and the population mean is $$\mu = 50. $$The difference between these values is an example of:

Accepted Answer

A sampling error

Question 17

A researcher wants to compare the effects of two diets. She pairs subjects based on age and gender, then randomly assigns one diet to each member of the pair. What experimental design is this?

Accepted Answer

Matched Pairs Design

Question 18

Which of the following is an example of categorical data?

Accepted Answer

The blood types of patients (A, B, AB, O)

Question 19

A hospital wants to estimate the average length of stay for patients. They divide patients into groups based on diagnosis and randomly select patients from each group. What sampling method is this?

Accepted Answer

Stratified sampling

Question 20

A researcher observes and records the eating habits of children at a school without intervening. What type of study is this?

Accepted Answer

Observational study

Introduction to Statistics: Key Concepts and Methods

Guida di studio - Domande di pratica

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