Statistics Chapter 2 Flashcards

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Questions and Answers

What is a frequency distribution?

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

What does frequency (f) represent?

The number of data entries in the class.

How many classes should there be?

Between 5 and 20.

How do you determine the range of a data set?

Highest number - Lowest number. Signup and view all the answers

What is the formula for determining class width?

Range / number of classes. Signup and view all the answers

What is the first step in finding class limits?

Use the minimum data entry as the lower limit of the first class. Signup and view all the answers

What are tally marks used for?

To make a tally mark for each data entry in the row of the appropriate class. Signup and view all the answers

How do you calculate the midpoint of a class?

(Lower class limit) + (Upper class limit) / 2. Signup and view all the answers

What does relative frequency represent?

Portion or percentage of the data that falls in a particular class. Signup and view all the answers

What is cumulative frequency?

The sum of the frequency for that class and all previous classes. Signup and view all the answers

What is a frequency histogram?

A bar graph that represents the frequency distribution. Signup and view all the answers

What are class boundaries?

The numbers that separate classes without forming gaps between them. Signup and view all the answers

What is a frequency polygon?

A line graph that emphasizes the continuous change in frequencies. Signup and view all the answers

What is the purpose of a relative frequency histogram?

Same shape and horizontal scale as regular histogram; vertical scale measures relative frequencies. Signup and view all the answers

What is an ogive?

A line graph that displays the cumulative frequency of each class at its upper class boundary. Signup and view all the answers

What is a stem and leaf plot?

Each number is separated into a stem and a leaf. Signup and view all the answers

What is a pie chart?

A circle divided into sectors that represent categories. Signup and view all the answers

How do you find the central angle for a pie chart?

Multiply 360 by the category's relative frequency. Signup and view all the answers

What is a Pareto chart?

A vertical bar graph in which the height of each bar represents frequency or relative frequency. Signup and view all the answers

What are paired data sets?

Each entry in one data set corresponds to one entry in a second data set. Signup and view all the answers

What is a time series chart?

Data set composed of quantitative entries taken at regular intervals over a period of time. Signup and view all the answers

Study Notes

Frequency Distribution

A frequency distribution is a table organizing data into classes or intervals, displaying counts for each class.

Frequency (f)

Frequency represents the count of data entries within a specific class.

Number of Classes

Typically, the number of classes in a frequency distribution ranges from 5 to 20, with lower class limits in the left column and upper class limits in the right.

Determining Range

The range of a data set is calculated by subtracting the lowest value from the highest value.

Determining Class Width

Class width is found by dividing the range by the number of classes.

Finding Class Limits

The first class’s lower limit is set by the minimum data entry; subsequent lower limits are obtained by adding the class width, while the upper limit of the first class is one less than the lower limit of the second class.

Tally Marks

Tally marks are used to record data entries within the corresponding class row, with total tally marks equating to the class frequency.

Midpoint

The midpoint of a class is calculated as the average of the lower and upper class limits, remaining spaced by the class width.

Relative Frequency

Relative frequency indicates the portion or percentage of total data that belongs to a particular class, calculated as class frequency divided by sample size.

Cumulative Frequency

Cumulative frequency is derived by summing the frequency of a class and all prior classes.

Frequency Histogram

A frequency histogram is a bar graph that illustrates the frequency distribution, with adjacent bars touching. The horizontal axis represents quantitative data, while the vertical axis measures frequency.

Class Boundaries

Class boundaries are defined numbers that differentiate classes without creating gaps between them.

Frequency Polygon

A frequency polygon is a line graph depicting continuous frequency changes, starting and ending on the horizontal axis and connecting points based on class midpoints.

Relative Frequency Histogram

Similar in shape to a regular histogram, a relative frequency histogram measures relative frequencies on the vertical axis.

Cumulative Frequency Graph (Ogive)

An ogive displays cumulative frequency against upper class boundaries, using a line graph format.

Constructing an Ogive

An ogive starts at the lower boundary of the first class with zero cumulative frequency and ends at the upper boundary of the last class, equating to the total sample size.

Stem and Leaf Plot

A stem and leaf plot separates numbers into a stem (leading digit(s)) and a leaf (trailing digit).

Dot Plot

A dot plot represents each data entry as a point plotted on a horizontal axis.

Pie Chart

A pie chart divides a circle into sectors that represent categories, with sector area proportional to each category’s frequency, applicable to qualitative data.

Finding Central Angle for Pie Chart

The central angle for any category is calculated by multiplying 360 by that category's relative frequency.

Pareto Chart

A Pareto chart is a vertical bar graph where bar heights denote frequency or relative frequency, organized in descending order, relevant for qualitative data.

Paired Data Sets

Paired data sets link entries from one data set to individual entries in another, typically visualized using scatter plots to represent relationships between two quantitative variables.

Time Series Chart

A time series chart is composed of quantitative data collected at regular intervals, with time on the horizontal axis and quantitative measures on the vertical axis, connecting points with lines.

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Description

Test your knowledge of key concepts in Statistics Chapter 2 with these flashcards. Learn about frequency distributions, classes, and how to determine ranges effectively. Perfect for reinforcing statistical principles and preparing for exams.