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Mathematics Worksheet
📐 Variance
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After this worksheet you can
Compute the population variance.Compute the sample variance (dividing by n − 1).Understand variance as the mean squared deviation.Recognise that variance is never negative.📚 Quick Recap
Variance measures how spread out a dataset is around its mean — a small variance means data points cluster tightly; a large variance means they're spread widely.
🧠 Section A · Concept Check ● BEGINNER 4 × 1 = 4
1The population variance of 3, 6, 9, 12 is:
2The sample variance of 3, 6, 9, 12 is:
3The population variance of 5, 5, 5, 5, 5 is:
4Sample variance divides the squared deviations by:
🧮 Section B · Problem Solving ● INTERMEDIATE 2 + 3×3 = 11
5Variance is the average deviation from the mean.
6Population variance divides by .
7Find the population variance of 3, 6, 9, 12.
8Find the sample variance of 3, 6, 9, 12.
9Find the population variance of 5, 5, 5, 5, 5.
🚀 Section C · Challenge ● CHALLENGE 5
10Find the population variance of 2, 4, 4, 4, 5, 5, 7, 9.
💭 Reflection — the most useful thing I learned:
A ___/4 B ___/11 C ___/5 Total ___/20
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✂ answer key — fold or cut before handing out
1-A 2-A 3-A 4-B | 5 squared 6 n 7 = 11.25 8 = 15 9 = 0 | 10 = 4