Question 1

A researcher collects the heights of every student in a university. Is this data set a population or a sample?

Accepted Answer

Population

Question 2

Which of the following best describes a parameter?

Accepted Answer

A numerical summary calculated from a population

Question 3

A survey of 50 randomly selected gym members finds an average workout duration of 48 minutes. Is this value a parameter or a statistic?

Accepted Answer

Statistic

Question 4

Which of the following is an example of qualitative data?

Accepted Answer

The favorite color of each student in a class

Question 5

Which of the following is a discrete quantitative variable?

Accepted Answer

The number of cars in a parking lot

Question 6

A researcher records the birth years of participants (e.g., 1990, 1985, 2001). What is the level of measurement for this data?

Accepted Answer

Interval

Question 7

Participants rate their satisfaction on a scale from 1 to 5. What is the level of measurement?

Accepted Answer

Ordinal

Question 8

Which level of measurement can describe both qualitative and quantitative data?

Accepted Answer

Ordinal

Question 9

A student claims that water at 80°F is twice as hot as water at 40°F. Why is this calculation incorrect?

Accepted Answer

Temperature in Fahrenheit is an interval variable, so ratios are meaningless

Question 10

A hospital records the birth weights of newborns. What is the level of measurement for this data?

Accepted Answer

Ratio

Question 11

A regional store manager randomly selects half of their locations to stay open an extra hour and compares profits. Is this an experiment or an observational study, and can causation be inferred?

Accepted Answer

Experiment; Yes, causation can be inferred

Question 12

A store surveys its target demographic and finds 86% would purchase a product after advertising. Is this an experiment or an observational study, and can causation be concluded?

Accepted Answer

Observational study; No, causation cannot be concluded

Question 13

Which of the following best describes a simple random sample?

Accepted Answer

Randomly selecting individuals so each group of the same size has an equal chance of being chosen

Question 14

A university with 60% undergraduates and 40% graduates surveys 60 random undergrads and 40 random grads. Is this a representative sample and/or a simple random sample?

Accepted Answer

Representative but not a simple random sample

Question 15

A bakery tests every 12th cookie produced. What type of sampling method is this?

Accepted Answer

Systematic sampling

Question 16

A quality control manager selects three random cases of units at the end of the day and tests all units in one of the cases. What type of sampling method is this?

Accepted Answer

Cluster sampling

Question 17

A quality control manager selects every tenth unit produced on the line for inspection. What type of sampling method is this?

Accepted Answer

Systematic sampling

Question 18

A university surveys 50 random undergraduates and 50 random graduates. What type of sampling method is this?

Accepted Answer

Stratified sampling

Question 19

A quality control manager uses a random number generator to select 100 of the 1500 units produced that day for testing. What type of sampling method is this?

Accepted Answer

Simple random sampling

Question 20

A quality control manager takes 10 random units from each of 10 machines to test for defects. What type of sampling method is this?

Accepted Answer

Stratified sampling

Chapter 1: Introduction to Data – Foundations of Statistics

Guida di studio - Domande di pratica

Study guide - Flashcard