Q: You are given a raw data set of daily high temperatures for 20 winter days: 12, 13, 17, 21, 24, 24, 26, 27, 27, 30, 32, 35, 37, 38, 41, 43, 44, 46, 58. What is the formula to calculate the width of each class interval if you want to create 5 classes?

$$\frac{\text{Range}}{\text{Number of classes}}$$

Q: What is the cumulative percentage for a class with a cumulative frequency of 14 in a data set of 20 observations?

$$\frac{14}{20} \times 100 = 70\%$$

Question 1

Which of the following best describes a contingency table?

Accepted Answer

A table that cross-tabulates the responses of two or more categorical variables to study patterns between them.

Question 2

You are given a raw data set of daily high temperatures for 20 winter days: 12, 13, 17, 21, 24, 24, 26, 27, 27, 30, 32, 35, 37, 38, 41, 43, 44, 46, 58. What is the formula to calculate the width of each class interval if you want to create 5 classes?

Accepted Answer

$$\frac{	ext{Range}}{	ext{Number of classes}}$$

Question 3

Which graphical display is most appropriate for visualizing the relationship between two numerical variables, such as height and weight of students?

Accepted Answer

Scatter plot

Question 4

A frequency distribution table for a numerical variable should generally have how many classes?

Accepted Answer

At least 5 but no more than 15

Question 5

What is the main difference between a histogram and a bar chart?

Accepted Answer

A histogram displays numerical data with adjacent bars and no gaps, while a bar chart displays categorical data with gaps between bars.

Question 6

If you want to compare the percentage of students in different majors at a university, which graphical display would be most appropriate?

Accepted Answer

Pie chart

Question 7

Given the following frequency distribution: Class 1 (3), Class 2 (6), Class 3 (5), Class 4 (4), Class 5 (2), what is the relative frequency of Class 4?

Accepted Answer

$$\frac{4}{20} = 0.20$$

Question 8

Which of the following is a common error that can create a false impression in a chart?

Accepted Answer

Compressing the vertical axis so differences appear exaggerated

Question 9

A Pareto chart is used to:

Accepted Answer

Show categories in descending order of frequency and highlight the 'vital few' causes

Question 10

When comparing two groups with different sample sizes, which type of frequency distribution should you use?

Accepted Answer

Relative or percentage frequency distribution

Question 11

Which visualization is best for showing the distribution and concentration of data in a small numerical data set?

Accepted Answer

Stem-and-leaf display

Question 12

What is the cumulative percentage for a class with a cumulative frequency of 14 in a data set of 20 observations?

Accepted Answer

$$\frac{14}{20} 	imes 100 = 70\%$$

Question 13

Which of the following is NOT a recommended best practice for constructing visualizations?

Accepted Answer

Use 3D or 'exploded' effects to make the chart more visually appealing

Question 14

A multidimensional contingency table is most useful for:

Accepted Answer

Discovering patterns and relationships among three or more categorical variables

Question 15

Which chart type is most likely to be misused by obscuring data or creating false impressions?

Accepted Answer

Pie chart with too many slices or improper scaling

Question 16

If you want to visualize the cumulative percentage of a numerical variable, which graphical display should you use?

Accepted Answer

Ogive (cumulative percentage polygon)

Question 17

Which Excel feature allows you to filter and query data interactively by clicking buttons representing unique values of a variable?

Accepted Answer

Slicer

Question 18

A time-series plot is best used to:

Accepted Answer

Study patterns in the values of a numeric variable over time

Question 19

Which of the following is a potential pitfall when organizing and visualizing variables?

Accepted Answer

Obscuring the data or creating false impressions

Question 20

In a bubble chart, what does the size of each point (bubble) represent?

Accepted Answer

The value of an additional variable, usually numerical

Chapter 2

Guida di studio - Domande di pratica

Study guide - Flashcard