Q: What is the formula for calculating the class width in a frequency distribution?

$$\text{Class width} = \frac{\text{Maximum data value} - \text{Minimum data value}}{\text{Number of classes}}$$

Q: Given the following data on the number of vehicles owned by 40 households: 0 (2), 1 (18), 2 (11), 3 (4), 4 (3), 5 (2), what percentage of households own exactly 2 vehicles?

$$\frac{11}{40} \times 100\% = 27.5\%$$

Question 1

Which of the following best describes a frequency distribution?

Accepted Answer

A table that lists all possible values of a variable and the number of times each value occurs.

Question 2

Given the following frequency distribution for favorite donut varieties: Glazed (8), Filled (7), Frosted (5), Plain (3), Other (7), what is the relative frequency of 'Frosted' donuts?

Accepted Answer

$$\frac{5}{30} = 0.167$$

Question 3

What is the formula for calculating the class width in a frequency distribution?

Accepted Answer

$$	ext{Class width} = \frac{	ext{Maximum data value} - 	ext{Minimum data value}}{	ext{Number of classes}}$$

Question 4

A histogram is most useful for which of the following purposes?

Accepted Answer

Displaying the shape, center, and spread of quantitative data.

Question 5

If a histogram has a longer tail on the right side, how is the data described?

Accepted Answer

Skewed to the right (positively skewed)

Question 6

Which of the following is NOT a feature of a dotplot?

Accepted Answer

It cannot be used to reconstruct the original data values.

Question 7

A cumulative frequency distribution is best described as:

Accepted Answer

A table that shows the total number of values that fall below the upper boundary of each class.

Question 8

Which type of graph is most appropriate for displaying the distribution of a categorical variable such as 'favorite donut variety'?

Accepted Answer

Bar graph

Question 9

A Pareto chart is different from a standard bar graph because:

Accepted Answer

The bars are arranged in descending order of frequency.

Question 10

Given the following data on the number of vehicles owned by 40 households: 0 (2), 1 (18), 2 (11), 3 (4), 4 (3), 5 (2), what percentage of households own exactly 2 vehicles?

Accepted Answer

$$\frac{11}{40} 	imes 100\% = 27.5\%$$

Question 11

Which of the following best describes a stem-and-leaf plot?

Accepted Answer

A display that separates each data value into a stem and a leaf, retaining the original data values.

Question 12

A pie chart is most useful for:

Accepted Answer

Showing the proportion of each category in a whole.

Question 13

If the sum of the relative frequencies in a distribution is 1, what should the sum of the percentages be?

Accepted Answer

100\%

Question 14

Which of the following is a key feature of a frequency polygon?

Accepted Answer

It uses line segments connected to points above class midpoints.

Question 15

A distribution of exam scores is bell-shaped and symmetric. Which term best describes this distribution?

Accepted Answer

Normal distribution

Question 16

In a cumulative frequency table, the cumulative frequency for a class is calculated by:

Accepted Answer

Adding the frequency for that class to the sum of all previous class frequencies.

Question 17

Which of the following graphs would be most appropriate to display the distribution of monthly rent amounts for 30 households?

Accepted Answer

Histogram

Question 18

A gap in a frequency distribution may indicate:

Accepted Answer

The data may come from two or more different populations.

Question 19

Which of the following is the correct formula for calculating the percentage for a category given its relative frequency?

Accepted Answer

$$	ext{Percentage} = (	ext{Relative frequency}) 	imes 100\%$$

Exploring Data with Tables and Graphs: Introductory Statistics Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard