Page 91 - IM_Algebra1_FL Print Sample.pdf

overall relative frequency, row relative frequency, and column relative frequency and the di erent interpretations of them.
• “Why does the second column in the table for number 2 add up to more than 100%?” (They are percentages of di erent wholes and it does not make sense to add them.)
• “How did you get the percentages for Group B in the table for number 3?” (I divided the values for Group B in the rst table by 80 (the total number in Group B) and multiplied by 100.)
• “Why are relative frequency tables useful? Give an example.” (They let you compare di erent categories to each other using percentages (relative frequencies) rather than the frequency. For example, you could compare the percentage of people in Group B who had colds lasting more than a week to the percentage of people in Group A who had colds lasting more than a week. This takes into account that there can be di erent numbers of people represented in each group.)
Lesson Synthesis
The mathematical purpose of this lesson is for students to understand how to create and interpret relative frequency tables. Here are some questions for discussion.
• “How do you create a relative frequency table?” (There are several di erent ways to do it. In short, you divide the numbers in a two-way table by a total or totals. The total can be for the entire table or the totals can be for each row or column depending on what relationship you are trying to nd.)
• “What are some categorical variables that you could use to make a frequency table? Share it with your partner.” (Here are some examples. Categorize students by whether or not they are on the honor roll and by their grade on the last test. Categorize students from two di erent sports teams and whether or not they are in band. Categorize students by their type of cell phone and what type of social media they use.)
2.4 Writing Sample
Cool Down: 0 minutes
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Student Task Statement
Eighty students are asked to write a sentence and record the hand they used to write with. A teacher then determines whether each sentence is written neatly or not. The results are summarized in the table.
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Teacher Guide
Algebra