Q: Given a data set with a minimum value of 105 and a maximum value of 283, and you want to create 7 classes, what is the appropriate class width?

$$\text{Class width} = \frac{283 - 105}{7} + 1 = 26$$

Q: What is the formula for the midpoint of a class interval?

$$\text{Midpoint} = \frac{\text{Lower class limit} + \text{Upper class limit}}{2}$$

Q: How do you calculate the relative frequency of a class?

$$\text{Relative frequency} = \frac{\text{Frequency of the class}}{\text{Sample size}}$$

Q: If a distribution is skewed right, which of the following is the correct order of mean, median, and mode?

$$\text{Mode} \u003c \text{Median} \u003c \text{Mean}$$

Question 1

Which of the following best describes a frequency distribution?

Accepted Answer

A table that shows classes or intervals of data with a count of the number of entries in each class.

Question 2

Given a data set with a minimum value of 105 and a maximum value of 283, and you want to create 7 classes, what is the appropriate class width?

Accepted Answer

$$	ext{Class width} = \frac{283 - 105}{7} + 1 = 26$$

Question 3

What is the formula for the midpoint of a class interval?

Accepted Answer

$$	ext{Midpoint} = \frac{	ext{Lower class limit} + 	ext{Upper class limit}}{2}$$

Question 4

If a frequency distribution has the following frequencies: 5, 8, 12, 10, 5, what is the cumulative frequency for the third class?

Accepted Answer

$$5 + 8 + 12 = 25$$

Question 5

Which of the following is NOT a property of a frequency histogram?

Accepted Answer

Bars are separated by gaps.

Question 6

How do you calculate the relative frequency of a class?

Accepted Answer

$$	ext{Relative frequency} = \frac{	ext{Frequency of the class}}{	ext{Sample size}}$$

Question 7

What is the main difference between a frequency polygon and a histogram?

Accepted Answer

A frequency polygon uses points connected by lines, while a histogram uses bars.

Question 8

Which of the following best describes class boundaries?

Accepted Answer

Numbers that separate classes without forming gaps between them.

Question 9

A cumulative frequency graph (ogive) is constructed by plotting which values?

Accepted Answer

Upper class boundaries and cumulative frequencies.

Question 10

Which of the following is true about the mean of a frequency distribution?

Accepted Answer

It is calculated as $$\bar{x} = \frac{\sum f x}{n}$$, where $$x is $$the midpoint of each class.

Question 11

If a distribution is skewed right, which of the following is the correct order of mean, median, and mode?

Accepted Answer

$$	ext{Mode} \u003c 	ext{Median} \u003c 	ext{Mean}$$

Question 12

Which of the following is a valid interpretation of a relative frequency histogram?

Accepted Answer

It shows the proportion of data entries in each class.

Question 13

What is the main purpose of a stem-and-leaf plot?

Accepted Answer

To show the distribution of data while retaining the original data values.

Question 14

Which of the following is NOT a measure of central tendency?

Accepted Answer

Range

Question 15

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

Accepted Answer

Qualitative data

Question 16

Which of the following statements about the mode is correct?

Accepted Answer

The mode is the value that occurs most frequently in a data set.

Question 17

If the sum of frequencies in a frequency distribution is 50, and the frequency for a class is 8, what is the relative frequency for that class?

Accepted Answer

$$\frac{8}{50} = 0.16$$

Question 18

Which of the following best describes a dot plot?

Accepted Answer

A graph that shows the distribution of data using dots above a number line.

Question 19

What is the first step in constructing a frequency distribution?

Accepted Answer

Decide the number of classes to include.

Question 20

Which of the following is true about open-ended classes in a frequency distribution?

Accepted Answer

They do not have a specific lower or upper class limit.

Descriptive Statistics: Frequency Distributions and Their Graphs

Guida di studio - Domande di pratica

Study guide - Flashcard