Question 1

Which step in the statistical investigation cycle is most directly associated with determining which variables and data sources are available to address a research question?

Accepted Answer

Consider Data

Question 2

A researcher wants to know if movies released on Fridays receive higher average ratings than movies released on other days. Which variables from the movieratings.csv dataset would be most relevant to answer this question?

Accepted Answer

release_day_of_week and vote_average

Question 3

In a two-way table summarizing seat belt usage by gender, which of the following best describes the variables being studied?

Accepted Answer

Seat belt usage and gender

Question 4

Given the following two-way table for seat belt usage among 14-17 year olds:

Male: Not Always = 2, Always = 3
Female: Not Always = 3, Always = 7

What percentage of the sample are female?

Use the formula:
$$
	ext{Percentage} = \frac{	ext{Number of females}}{	ext{Total sample size}} 	imes 100
$$

Accepted Answer

60%

Question 5

A statistics class has 300 students. If 30% do not always wear a seat belt, how many students is this?

Use the formula:
$$
	ext{Number} = 	ext{Total students} 	imes 	ext{Percent as decimal}
$$

Accepted Answer

90

Question 6

In another class, 20% of students do not always wear seat belts, which equals 43 students. How many students are in the class?

Use the formula:
$$
	ext{Total students} = \frac{	ext{Number of students}}{	ext{Percent as decimal}}
$$

Accepted Answer

215

Question 7

A two-way table records gender and handedness:

Male: Left = 10, Right = 40
Female: Left = 5, Right = 35

What percent of the class is left-handed?

Use the formula:
$$
	ext{Percent left-handed} = \frac{	ext{Total left-handed}}{	ext{Total students}} 	imes 100
$$

Accepted Answer

15%

Question 8

Using the same table:

Male: Left = 10, Right = 40
Female: Left = 5, Right = 35

What percent of the males are left-handed?

Use the formula:
$$
	ext{Percent left-handed males} = \frac{	ext{Left-handed males}}{	ext{Total males}} 	imes 100
$$

Accepted Answer

20%

Question 9

When comparing the number of injuries in different sports, why is it important to use percentages or rates rather than raw counts?

Accepted Answer

Percentages account for differences in the number of participants in each sport

Question 10

In the Youth Risk Survey two-way table, if you want to know whether males are more likely than females to not always wear seat belts, which calculation would best help you answer this?

Accepted Answer

Compare the percentage of males who do not always wear seat belts to the percentage of females who do not always wear seat belts

Question 11

Which of the following best describes a two-way table?

Accepted Answer

A table that displays the frequency of combinations of two categorical variables

Question 12

A researcher is investigating whether cell phones cause cancer. According to the statistical investigation cycle, what is the next step after asking the research question?

Accepted Answer

Consider Data

Question 13

If a two-way table shows that 5 out of 15 females are left-handed, what is the percentage of left-handed females?

Use the formula:
$$
	ext{Percentage} = \frac{	ext{Left-handed females}}{	ext{Total females}} 	imes 100
$$

Accepted Answer

33.3%

Question 14

Which of the following is NOT a reason to organize data before analysis?

Accepted Answer

To reduce the amount of data collected

Question 15

A class has 200 students. If 40 students are left-handed, what percent of the class is left-handed?

Use the formula:
$$
	ext{Percent} = \frac{40}{200} 	imes 100
$$

Accepted Answer

20%

Question 16

Which of the following best illustrates the importance of the 'Analyze Data' step in the statistical investigation cycle?

Accepted Answer

Visualizing the data to identify trends and patterns

Question 17

If a two-way table shows that 2 males and 3 females do not always wear seat belts, and 3 males and 7 females always wear seat belts, what is the total sample size?

Accepted Answer

15

Question 18

Which of the following is a critical insight when comparing groups in statistics?

Accepted Answer

Groups should be similar and comparisons should use percentages or rates

Question 19

A two-way table shows the following injuries for sports:
Baseball: 165,842
Basketball: 501,251
Football: 451,961
Soccer: 208,214

If you want to determine which sport is most dangerous, what additional information would you need?

Accepted Answer

The number of participants in each sport

Question 20

Which formula would you use to calculate the percentage of students in a class who do not always wear seat belts, given the total number of students and the number who do not always wear seat belts?

$$
	ext{Percentage} = \frac{	ext{Number who do not always wear seat belts}}{	ext{Total students}} 	imes 100
$$

Accepted Answer

The formula shown above

Introduction to Statistics: Investigating and Organizing Data

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