$$\frac{\text{frequency of 2 pets}}{\text{sum of all frequencies}}$$

$$\frac{6}{15} \times 100 = 40\%$$

Question 1

Which of the following is a categorical variable in a study of breakfast cereals?

Accepted Answer

Manufacturer

Question 2

A researcher records the number of languages spoken by each student in a class. What type of variable is this?

Accepted Answer

Discrete quantitative variable

Question 3

Which graphical summary is most appropriate for displaying the distribution of a categorical variable such as 'type of residence'?

Accepted Answer

Pie chart

Question 4

A company wants to visualize the distribution of monthly salaries among its employees. Which graph should they use?

Accepted Answer

Histogram

Question 5

Which of the following best describes a continuous quantitative variable?

Accepted Answer

Amount of coffee in an 8-ounce cup

Question 6

Given a frequency table for the number of pets owned by students, how do you calculate the proportion of students who own exactly 2 pets?

Accepted Answer

$$\frac{	ext{frequency of 2 pets}}{	ext{sum of all frequencies}}$$

Question 7

Which feature is most important when summarizing a categorical variable?

Accepted Answer

The relative number of observations in each category

Question 8

A stem-and-leaf plot is most similar to which other graphical summary?

Accepted Answer

Histogram

Question 9

In a survey, students are asked their favorite ice cream flavor. What type of variable is 'favorite flavor'?

Accepted Answer

Categorical variable

Question 10

Which of the following is NOT a key feature of a bar graph?

Accepted Answer

Bars represent intervals of continuous data

Question 11

A frequency table for a continuous quantitative variable is constructed by:

Accepted Answer

Grouping values into non-overlapping intervals and counting observations in each interval

Question 12

If a bar graph is ordered from tallest to shortest bar, it is called a:

Accepted Answer

Pareto chart

Question 13

Which of the following is an example of a discrete quantitative variable?

Accepted Answer

Number of children in a family

Question 14

A dot plot is best used for which type of variable?

Accepted Answer

Quantitative variable with a small to moderate dataset

Question 15

Which of the following statements about pie charts is TRUE?

Accepted Answer

Each slice of a pie chart represents a category's proportion of the total

Question 16

A frequency table shows that 6 students scored between 90 and 95 on a test out of 15 students. What is the percentage of students in this interval?

Accepted Answer

$$\frac{6}{15} 	imes 100 = 40\%$$

Question 17

Which variable from the US Census 2000 dataset is quantitative?

Accepted Answer

Annual income

Question 18

When constructing a histogram, what is the first step?

Accepted Answer

Divide the range of the data into intervals of equal width

Question 19

Which of the following is a key reason to use a stem-and-leaf plot instead of a histogram for a small dataset?

Accepted Answer

It displays the original data values

Question 20

A survey asks respondents to select their payment method (cash, credit, debit, mobile). What type of variable is 'payment method'?

Accepted Answer

Categorical variable

(Lecture 2) Types of Data and Graphical Summaries in Statistics

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