Question 1

Which of the following best describes the difference between a population and a sample in statistics?

Accepted Answer

A population includes all individuals of interest, while a sample is a subset of the population.

Question 2

Which of the following is an example of a qualitative variable?

Accepted Answer

Favorite color of survey respondents

Question 3

A researcher wants to estimate the average commute time for all employees in a company. She surveys 50 randomly selected employees. In this context, what is the sample?

Accepted Answer

The 50 randomly selected employees

Question 4

Which of the following is a discrete variable?

Accepted Answer

Number of cars in a parking lot

Question 5

What is the main purpose of inferential statistics?

Accepted Answer

To make predictions or draw conclusions about a population based on a sample

Question 6

Which of the following is an example of a continuous variable?

Accepted Answer

Amount of milk in a glass

Question 7

A parameter is best defined as:

Accepted Answer

A numerical summary of a population

Question 8

Which of the following sampling methods gives every member of the population an equal chance of being selected?

Accepted Answer

Simple random sampling

Question 9

Suppose you want to study the average test score of all students in a university. You randomly select 5 students from each department. What type of sampling is this?

Accepted Answer

Stratified sampling

Question 10

Which of the following is NOT a level of measurement?

Accepted Answer

Fractional

Question 11

A researcher records the blood types (A, B, AB, O) of patients in a hospital. What is the level of measurement for this data?

Accepted Answer

Nominal

Question 12

Which formula would you use to calculate the mean of a data set with values $$x_1$$, $$x_2$$, ..., x_n$$?

Accepted Answer

$$\frac{\sum_{i=1}^{n} x_i}{n}$$

Question 13

If the heights (in cm) of five students are 150, 160, 170, 180, and 190, what is the median height?

Accepted Answer

170

Question 14

Which of the following best describes the mode of a data set?

Accepted Answer

The value that appears most frequently

Question 15

Given the data set: 2, 4, 4, 6, 8, what is the range?

Accepted Answer

6

Question 16

Which formula is used to calculate the variance of a population with values $$x_1$$, $$x_2$$, ..., x_N$$ and mean $$\mu$$?

Accepted Answer

$$\frac{\sum_{i=1}^{N} (x_i - \mu)^2$}{N}$$

Question 17

A company wants to know if there is a relationship between employee age and job satisfaction. Which branch of statistics should they use?

Accepted Answer

Inferential statistics

Question 18

Which of the following is an example of ordinal data?

Accepted Answer

Ranking of students as 1st, 2nd, 3rd in a competition

Question 19

If a data set has a mean of 50 and a standard deviation of 5, what is the z-score for a value of 60?

Accepted Answer

$$z = \frac{60 - 50}{5} = 2$$

Question 20

Which of the following best describes systematic sampling?

Accepted Answer

Selecting every kth individual from a list after a random start

Introductory Statistics: Key Concepts and Study Guide

Guida di studio - Domande di pratica

Study guide - Flashcard