IM Alg1.3.2 Lesson: Relative Frequency Tables
Several adults in a school building were asked about their highest degree completed and whether they were a teacher.
What do you notice? What do you wonder?
200 people were asked if they prefer dogs or cats, and whether they live in a rural or urban setting.
The actual values collected from the survey are in the first table.
The next table shows the percentage of each column that had a certain pet preference in a column relative frequency table. The segmented bar graph represents the same information graphically.
The last table shows the percentage of each row that live in a certain area in a row relative frequency table. The segmented bar graph represents the same information graphically.
For each relative frequency table, select a percentage and explain how numbers from the original table were used to get the percentage.
What percentage of those surveyed live in an urban area and prefer dogs?
Among the people surveyed who prefer dogs, what percentage of them live in an urban setting?
What percentage of people surveyed who live in an urban setting prefer dogs?
How many of the people responded that they prefer dogs and live in an urban setting?
Among the people surveyed, are there more people who prefer dogs or cats?
Your pet food company has access to a billboard in a rural setting. Would you recommend advertising dog food or cat food on this billboard? Which table did you use to make this decision? Explain your reasoning.
In an experiment to test the effectiveness of vitamin C on the length of colds, two groups of people with colds are given a pill to take once a day.
The pill for one of the groups contains 1,000 mg of vitamin C, while the other group takes a placebo pill. The researchers record the results in a table.
First, the researchers want to know what percentage (to the nearest whole percent) of people are in each combination of categories. Fourteen percent of all the participants had a cold that lasted less than a week and were in group A. What percentage of all the participants had a cold that lasted less than a week and were in group B? Complete the rest of the relative frequency table with the corresponding percentages.
Next, the researchers notice that, among participants who had colds that lasted less than a week, 37% were in group A. Among participants who had colds that lasted a week or more, what percentage were in group B? Complete the table with the corresponding percentages.
Finally, the researchers notice that, among the participants in group A, 48% had colds that lasted less than one week. Among the participants in group B, how many had colds that lasted a week or more? Complete the table with the corresponding percentages.
To understand the results, the researchers want to know: Among people whose colds lasted less than a week, what percentage are in group B? Explain your reasoning.
If the researchers believe that vitamin C has a small effect on the length of a cold, which group most likely got the pills containing vitamin C? Explain your reasoning.
A teacher surveyed a group of 25 8th graders and a group of 20 12th graders who indicated they knew a computer programming language.
Python and Scratch are programming languages. The results from the 8t-grade survey are displayed in the two-way table.
The results from the 12th-grade survey are displayed in the two-way table.
Which programming language did a majority of 8th graders surveyed know best?
Which programming language did a majority of 12th graders surveyed know best?
How many of 12th graders surveyed reported that they were taught a programming language at school?
What percentage of 8th graders surveyed reported that they knew Python the best and were not taught a programming language at school?
Why is it difficult to decide if 12th graders or 8th graders use Python more with the way the information is given in the tables?