Two Way Tables Presented by Mr. Laws Allowance No Allowance Total Chores 3 2 5 No Chores 1 4 8 Presented by Mr. Laws

Standard 8.SP.4 Use relative frequency to describe associations between variables: Understand that patterns of association can also be seen in bivariate categorical data by displaying frequencies and relative frequencies in a two-way table. Construct and interpret a two-way table summarizing data on two categorical variables collected from the same subjects. Use relative frequencies calculated for rows or columns to describe possible association between the two variables.

Essential Question How do I construct and interpret a two-way table summarizing data on two categorical variables ?

Key Vocabulary Words Frequency – is the amount or a number of times that data appears in a data set. Frequency Distribution – is a method used to group data into a meaningful pattern. Relative Frequency (RF) – is the number of data written as a percentage (%). Joint Relative Frequency (JRF)– is found by dividing a frequency that is not in the total row or total column by the grand total. Marginal Relative Frequency (MRF)– is found by dividing a row total or a column total by the grand total. Conditional Relative Frequency (CFA) – is found by dividing a frequency that is not in the Total row or the Total column by the frequency’s row total or column total.

What is a two-way table? A two –way table is a table that displays two or more – variable data by organizing it into rows and columns. Dog No Dog Total Cat 6 4 10 No Cat 5 15 16 9 25

How do I create a Two –Way table? Start with organizing a survey of two categories: Student Abby John Julie Mike Deb Chris Gus Lynn Chores Yes No Allowance Create a two – way table based on the data you collected. Allowance No Allowance Total Chores No Chores

What is a Relative Frequency (RF) Two – Way Table? Allowance No Allowance Total Chores 3 2 5 No Chores 1 4 8 Change the frequency data into relative frequency (%) Allowance No Allowance Total Chores 3/8 = 37.5% 2/8 = 25% 5/8 = 62.5% No Chores 1/8 = 12.5% 4/8 = 50% 8/8 =100%

Two – Way RF table by Columns Allowance No Allowance Total Chores 3 2 5 No Chores 1 4 8 Allowance No Allowance Total Chores 3/4 = 75% 2/4= 50% 5/8 = 62.5% No Chores 1/4 = 25% 2/4 = 50% 3/8 = 37.5% 4/4 = 100% 8/8 =100%

Two – Way RF table by Rows Allowance No Allowance Total Chores 3 2 5 No Chores 1 4 8 Allowance No Allowance Total Chores 3/5 = 60% 2/5= 40% 5/5 = 100% No Chores 1/3 = 33% 2/3 = 67% 3/3 = 100% 4/8= 50% 4/8 = 50% 8/8 =100%

Summary Can you answer the essential question? Do you have any additional questions pertaining to the lesson? Is there any thing else you would like to know about this lesson?