Q: What is the formula for calculating the relative frequency of a category?

$$\text{Relative Frequency} = \frac{\text{Frequency of the category}}{\text{Sum of all frequencies}}$$

Q: Given a data set with a smallest value of 65 and a largest value of 322.61, and you want to create 11 classes, what is the formula for determining the class width?

$$\text{Class Width} = \frac{\text{Largest Value} - \text{Smallest Value}}{\text{Number of Classes}}$$

Question 1

Which of the following best describes a frequency distribution for qualitative data?

Accepted Answer

A table that lists each category of data and the number of occurrences for each category.

Question 2

What is the formula for calculating the relative frequency of a category?

Accepted Answer

$$	ext{Relative Frequency} = \frac{	ext{Frequency of the category}}{	ext{Sum of all frequencies}}$$

Question 3

A physical therapist collects data on the body part requiring rehabilitation for 30 patients. Which graphical display would be most appropriate to summarize this qualitative data?

Accepted Answer

Bar graph

Question 4

Which of the following statements about Pareto charts is correct?

Accepted Answer

Bars are drawn in decreasing order of frequency or relative frequency.

Question 5

Why should relative frequencies be used instead of frequencies when comparing two data sets of different sizes using side-by-side bar graphs?

Accepted Answer

Relative frequencies account for differences in sample or population sizes, making comparisons fair.

Question 6

Which of the following is NOT a guideline for constructing good graphics?

Accepted Answer

Use three-dimensional charts to make the data more visually appealing.

Question 7

A histogram is different from a bar graph because:

Accepted Answer

The rectangles in a histogram touch each other, representing continuous data.

Question 8

Given a data set with a smallest value of 65 and a largest value of 322.61, and you want to create 11 classes, what is the formula for determining the class width?

Accepted Answer

$$	ext{Class Width} = \frac{	ext{Largest Value} - 	ext{Smallest Value}}{	ext{Number of Classes}}$$

Question 9

Which of the following best describes a bell-shaped distribution?

Accepted Answer

The highest frequency occurs in the middle and frequencies tail off to the left and right.

Question 10

A time-series plot is most appropriate for which type of data?

Accepted Answer

Data measured at different points in time.

Question 11

Which of the following could make a graph misleading?

Accepted Answer

Using an inconsistent scale on the axes.

Question 12

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

Accepted Answer

Small sets of quantitative data.

Question 13

Which of the following is a potential problem with starting the vertical axis of a bar graph at a value other than zero?

Accepted Answer

It can exaggerate or minimize differences between categories, misleading the reader.

Question 14

If a distribution is skewed right, which of the following is true?

Accepted Answer

The tail to the right of the peak is longer than the tail to the left.

Question 15

Which of the following is NOT a recommended practice when constructing a pie chart?

Accepted Answer

Exaggerating the size of one sector to draw attention to it.

Question 16

A researcher wants to summarize the number of customers arriving at a restaurant in 40 intervals. The data are discrete and have many different values. What is the best way to organize the data?

Accepted Answer

Create classes using intervals of numbers and construct a histogram.

Question 17

Which of the following is a reason why constructing frequency distributions is considered an 'art form'?

Accepted Answer

There is not one correct frequency distribution for a particular set of data.

Question 18

Which of the following is a guideline for determining the lower class limit of the first class when organizing continuous data?

Accepted Answer

Choose the smallest observation in the data set or a convenient number slightly lower than the smallest observation.

Question 19

Which of the following best describes a uniform distribution?

Accepted Answer

The frequency of each value is evenly spread out across the values.

Question 20

Which of the following is a common error that can make a pie chart misleading?

Accepted Answer

Making one sector larger than its proportional frequency.

Summarizing Data in Tables and Graphs – Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard