Understandable Statistics

Questions and Answers

What is a frequency table?

A table showing the maximum and minimum data values.

A table that partitions data into classes and shows the count of data values in each class. (correct)

A table that shows the average of data values.

A table that lists every individual data value.

What is a probability distribution?

An estimate of the probability of an event based on the relative frequency, applicable when the random sample is large enough.

What is class width?

The difference between the lower class limit of one class and the lower class limit of the next class.

What is the lower class limit?

The lowest data value that can fit in a class. Signup and view all the answers

What is class frequency?

The number of tally marks corresponding to a class. Signup and view all the answers

What is the midpoint of a class?

The center of each class, calculated by adding the lower and upper limits and dividing by 2. Signup and view all the answers

What is a histogram?

A visual display of frequency table data using bars. Signup and view all the answers

What does a relative-frequency table show?

The proportion of all data values that fall into each class. Signup and view all the answers

What is a relative-frequency histogram?

A visual representation of relative-frequency table data using bars. Signup and view all the answers

What is a mound-shaped symmetric distribution?

A histogram where both sides are approximately the same when folded vertically down the middle. Signup and view all the answers

What is a uniform distribution?

A histogram in which every class has equal frequency. Signup and view all the answers

What does skewed left mean?

A histogram where one tail is stretched longer on the left. Signup and view all the answers

What does skewed right mean?

A histogram where one tail is stretched longer on the right. Signup and view all the answers

Study Notes

Frequency Table

A frequency table organizes large quantitative data into distinct classes or intervals, displaying how many data values belong to each class.
Key steps involve deciding the number of classes, calculating class width, determining data ranges, tallying data, finding class frequencies, computing midpoints, and establishing class boundaries.

Probability Distribution

A large enough random sample allows estimation of event probability through relative frequency, forming a probability distribution.

Class Width

Class width is defined as the difference between consecutive lower class limits, calculated by dividing the range of data (largest value - smallest value) by the desired number of classes, rounded up to the nearest whole number.

Class Limits

Lower class limit is the smallest value in a class, while the upper class limit is the largest value.
Establish lower limits using the smallest data value and add the class width incrementally to determine subsequent lower limits, then define the corresponding upper limits.

Class Frequency

Class frequency represents the number of tally marks recorded for each class in the frequency table.

Class Midpoint

The midpoint (or class mark) of each class is calculated by averaging the lower and upper limits of that class, serving as a representative value for the entire class.

Histogram

A histogram visually represents frequency table data, requiring the creation of a frequency table and plotting class boundaries against frequencies on a bar graph.
Each bar's height reflects the corresponding class frequency, and the alignment of data values to class limits can be done using class boundaries or midpoints.

Relative-Frequency Table

This type of table shows the proportion of total data values within each class by computing the relative frequency as the ratio of class frequency to the total sample size.

Relative-Frequency Histogram

Similar to a standard histogram, it represents relative frequency data, with bars drawn based on class boundaries and heights reflecting class relative frequencies.

Mound-Shaped Symmetric Distribution

A histogram exhibiting this shape has both sides that are relatively equal when folded vertically, indicating a symmetrical distribution.

Uniform Distribution

In a uniform distribution, every class has equal frequency, resulting in a symmetrical histogram where all bars maintain the same height.

Skewness

Skewed left signifies a histogram where the left tail is longer than the right, indicating more data values concentrated on the right side.
Skewed right implies the opposite, with the right tail being longer than the left, indicating more concentration on the left side.

Description

Test your knowledge with flashcards from Chapter 2 of Understandable Statistics. This chapter focuses on frequency tables, helping you understand how to organize and interpret quantitative data effectively. Prepare to master the concepts of classes, intervals, and data distribution.

Understandable Statistics - Chapter 2