Q: Given the following two-way table, what percentage of males are gamers? $$\begin{array}{ccc} & \text{Male} & \text{Female} \\ \text{Gamer} & 6 & 2 \\ \text{Non-gamer} & 3 & 4 \\ \end{array}$$

$$\frac{6}{9} \times 100\% = 67\%$$

Question 1

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

Accepted Answer

A population includes all possible data values for a variable of interest, while a sample is a subset of the population.

Question 2

A researcher collects the heights of all bridges in a city. What type of variable is 'height of a bridge'?

Accepted Answer

Numerical

Question 3

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

Accepted Answer

Type of pets owned (cat, dog, etc.)

Question 4

In a study, the gender variable is coded as 1 for female and 0 for other/intersex. What is the purpose of this coding?

Accepted Answer

To make storing and reading categorical data easier in a spreadsheet

Question 5

Which of the following best describes a histogram?

Accepted Answer

A graph where observations are grouped into intervals (bins) and each bin is represented by a bar whose height is proportional to the frequency.

Question 6

Why are percentages or rates preferred over counts when comparing groups of different sizes?

Accepted Answer

Percentages or rates account for differences in group sizes, making comparisons fair.

Question 7

A study finds that students at universities near casinos have more gambling problems. Can we conclude that proximity to casinos causes gambling problems?

Accepted Answer

No, because the study is observational and cannot establish causality.

Question 8

Which of the following is a confounding variable in a study comparing LSAT scores of students who took a prep course versus those who did not?

Accepted Answer

Student motivation

Question 9

Which of the following is NOT a characteristic of a well-designed controlled experiment?

Accepted Answer

Subjects are assigned to groups based on their preferences.

Question 10

A bar chart is most appropriate for which type of data?

Accepted Answer

Categorical data

Question 11

Given the following two-way table, what percentage of males are gamers?

$$\begin{array}{ccc}
 & 	ext{Male} & 	ext{Female} \
	ext{Gamer} & 6 & 2 \
	ext{Non-gamer} & 3 & 4 \
\end{array}$$

Accepted Answer

$$\frac{6}{9} 	imes 100\% = 67\%$$

Question 12

Which of the following is a key difference between a histogram and a bar chart?

Accepted Answer

Histogram bars must touch, while bar chart bars do not touch.

Question 13

A distribution with two main mounds is called:

Accepted Answer

Bimodal

Question 14

Which of the following is a potential source of error when an outlier is observed in a data set?

Accepted Answer

A data entry typo

Question 15

Why is it important for the frequency scale in a bar chart to begin at zero?

Accepted Answer

To avoid creating the illusion of greater differences between categories

Question 16

In a controlled experiment on multitasking in the classroom, what was the main conclusion?

Accepted Answer

Multitasking caused the difference in comprehension test scores.

Question 17

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

Accepted Answer

The category that occurs most often

Question 18

A pie chart is generally not recommended by statisticians because:

Accepted Answer

It is harder to compare the sizes of wedges accurately.

Question 19

Which of the following is an example of high variability in a categorical data set?

Accepted Answer

Many observations spread across many different categories

Introduction to Data and Visualizing Data in Statistics

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