Unit 6 · Identifying Sufficient Information
47 vs 18 Detentions — Is That a Fair Comparison?
Lesson 6 of 12
About this lesson
Ms Flint sees that Class 1 got 47 detentions and Class 2 got only 18, and immediately concludes Class 2 students are better behaved. But wait — did she ask whether both teachers use detention the same way? This question introduces one of the most important critical thinking concepts: a number is only a fair comparison if the measuring stick is the same for everyone.
Chapters
Question
| The school principal, Ms Flint, is looking at the school records for last term to see which class has the best-behaved students.
| She notices that students in Class 1, who are taught by Mr Avery, were given 47 lunchtime detentions in total last term. Students in Class 2, who are taught by Mr Bailey, were only given 18. |
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Ms Flint: "That's interesting – it clearly shows that students in Class 2 are much better behaved than students in Class 1."
Which one of the following sentences shows the mistake Ms Flint has made?
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