standard_description: Interpret multiplication as scaling (resizing), by:
- Explaining why multiplying a given number by a fraction greater than 1 results in a product greater than the given number (recognizing multiplication by whole numbers greater than 1 as a familiar case); explaining why multiplying a given number by a fraction less than 1 results in a product smaller than the given number; and relating the principle of fraction equivalence a/b = (n×a)/(n×b) to the effect of multiplying a/b by 1.
- Comparing the size of a product to the size of one factor on the basis of the size of the other factor, without performing the indicated multiplication.
problem_activity: Task
The 54 students in one of several middle school classrooms were asked two questions about musical preferences: “Do you like rock?” “Do you like rap?” The responses are summarized in the table below.
{"table": [{"tbody": [{"tr": [{"td": [{}], "th": [{"_value": "Likes Rap"}, {"_value": "Doesn't Like Rap"}, {"_value": "Row Totals"}]}, {"th": [{"_value": "Likes Rock"}], "td": [{"_value": "27"}, {"_value": "6"}, {"_value": "33"}]}, {"th": [{"_value": "Doesn't Like Rock"}], "td": [{"_value": "4"}, {"_value": "17"}, {"_value": "21"}]}, {"th": [{"_value": "Column Totals"}], "td": [{"_value": "31"}, {"_value": "23"}, {"_value": "54"}]}]}]}]}
Is this a random sample, one that fairly represents the opinions of all students in the middle school?
What percentage of the students in the classroom like rock?
Is there evidence in this sample of a positive association in this class between liking rock and liking rap? Justify your answer by pointing out a feature of the table that supports it.
Explain why the results for this classroom might not generalize to the entire middle school.


aligns: no