Common Core: 8th Grade Math : Statistics & Probability

Study concepts, example questions & explanations for Common Core: 8th Grade Math

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Example Questions

Example Question #1 : Use Data To Construct And Interpret A Two Way Table: Ccss.Math.Content.8.Sp.A.4

A middle school teacher conducted a survey of the  grade class and found that  students were athletes and  of those students drink soda. There were  students that were not athletes, but drank soda. Last, they found that  students did not have a curfew nor were on honor roll. Given this information, how many students drink soda?  

 

Possible Answers:

Correct answer:

Explanation:

To help answer this question, we can construct a two-way table and fill in our known quantities from the question.

The columns of the table will represent the students who are athletes or are not athletes and the rows will contain the students who drink soda or do not drink soda. The first bit of information that we were given from the question was that  students were athletes; therefore,  needs to go in the "athlete" column as the row total. Next, we were told that of those students,  drinks soda; therefore, we need to put  in the "athlete" column and in the "drinks soda" row. Then, we were told that  students were not athletes, but drink soda, so we need to put  in the "not an athlete" column and the "drinks soda" row. Finally, we were told that  students are not athletes or soda drinkers, so  needs to go in the "not an athlete" column and "doesn't drink soda" row. If done correctly, you should create a table similar to the following: 

Screen shot 2016 03 25 at 2.05.31 pm

 

Our question asked how many students drink soda. We add up the numbers in the "drinks soda" row to get the total:

This means that  students drink soda. 

Example Question #241 : Data Analysis

A teacher at a high school conducted a survey of freshman and found that  students had a curfew and  of those students were also honor roll students. There were  students that did not have a curfew, but were on the honor roll. Last, they found that  students did not have a curfew nor were on the honor roll. Given this information, how many students were not on the honor roll? 

 

Possible Answers:

Correct answer:

Explanation:

To help answer this question, we can construct a two-way table and fill in our known quantities from the question.

The columns of the table will represent the students who have a curfew or do not have a curfew and the rows will contain the students who are on honor roll  or are not on honor roll. The first bit of information that we were given from the question was that  students had a curfew; therefore,  needs to go in the "curfew" column as the row total. Next, we were told that of those students,  were on honor roll; therefore, we need to put  in the "curfew" column and in the "honor roll" row. Then, we were told that  students do not have a curfew, but were on honor roll, so we need to put  in the "no curfew" column and the "honor roll" row. Finally, we were told that  students do not have a curfew or were on honor roll, so  needs to go in the "no curfew" column and "no honor roll" row. If done correctly, you should create a table similar to the following: 

Screen shot 2016 03 25 at 11.37.50 am

 

Our question asked how many students were not on honor roll. We add up the numbers in the "no honor roll" row to get the total, but first we need to fill in a gap in our table, students who have a curfew, but were not on honor roll. We can take the total number of students that have a curfew, , and subtract the number of students who are on honor roll, 

This means that  students who have a curfew, aren't on honor roll. 

Now, we add up the numbers in the "no honor roll" row to get the total:

This means that  students were not on honor roll. 

Example Question #251 : Data Analysis

A middle school teacher conducted a survey of the  grade class and found that  students were athletes and  of those students drink soda. There were  students that were not athletes, but drank soda. Last, they found that  students were neither athletes nor drank soda. Given this information, how many students don't drink soda? 

Possible Answers:

Correct answer:

Explanation:

To help answer this question, we can construct a two-way table and fill in our known quantities from the question.

The columns of the table will represent the students who are athletes or are not athletes and the rows will contain the students who drink soda or do not drink soda. The first bit of information that we were given from the question was that  students were athletes; therefore,  needs to go in the "athlete" column as the row total. Next, we were told that of those students,  drinks soda; therefore, we need to put  in the "athlete" column and in the "drinks soda" row. Then, we were told that  students were not athletes, but drink soda, so we need to put  in the "not an athlete" column and the "drinks soda" row. Finally, we were told that  students are not athletes or soda drinkers, so  needs to go in the "not an athlete" column and "doesn't drink soda" row. If done correctly, you should create a table similar to the following: 

Screen shot 2016 03 25 at 2.05.31 pm

 

Our question asked how many students don't drink soda. We add up the numbers in the "doesn't drink soda" row to get the total, but first we need to fill in a gap in our table, students who were athletes, but don't drink soda. We can take the total number of students who are athletes, , and subtract the number of students who drink soda, 

This means that  students who are athletes, don't drink soda.  

Now, we add up the numbers in the "doesn't drink soda" row to get the total:

This means that  students don't drink soda. 

Example Question #5 : Completing Incomplete Tables

A middle school teacher conducted a survey of the  grade class and found that  students were athletes and  of those students drink soda. There were  students that were not athletes, but drank soda. Last, they found that  students neither drank soda nor were athletes. Given this information, how many students were not athletes? 

 

Possible Answers:

Correct answer:

Explanation:

To help answer this question, we can construct a two-way table and fill in our known quantities from the question.

The columns of the table will represent the students who are athletes or are not athletes and the rows will contain the students who drink soda or do not drink soda. The first bit of information that we were given from the question was that  students were athletes; therefore,  needs to go in the "athlete" column as the row total. Next, we were told that of those students,  drinks soda; therefore, we need to put  in the "athlete" column and in the "drinks soda" row. Then, we were told that  students were not athletes, but drink soda, so we need to put  in the "not an athlete" column and the "drinks soda" row. Finally, we were told that  students are not athletes or soda drinkers, so  needs to go in the "not an athlete" column and "doesn't drink soda" row. If done correctly, you should create a table similar to the following: 

Screen shot 2016 03 25 at 2.05.31 pm

 

Our question asked how many students were not athletes. We add up the numbers in the "not an athlete" column to get the total:

This means that  students were not athletes. 

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