Practice Summary (8) - Standard Deviation & Variance - IB 10 Mathematics – Group 5, Statistics & Probability

Practice: Summary

Lesson 8Standard Deviation & Variance

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8 questions

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2 cards from this section. Quick, good the night before a test.
Exercise
6 questions · about 4 min · pass mark 70%. Hints available.
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Quiz
2 questions · about 1 min · pass mark 70%. Hints available.
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6 sample questions

Question 1.
Find the mean of the data set: 5, 10, 15.
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Sum the numbers and divide by how many values there are.
Question 2.
Calculate the deviation for the number 6 from the mean of the data set: 4, 5, 7.
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Find the mean first, then subtract it from 6.
3Question 3.
What is the formula for variance of a sample?
- \\(\\frac{\\sum (x - \\mu)^2}{N}\\)
- \\(\\frac{\\sum (x - \\bar{x})^2}{n - 1}\\)
- \\(\\sum (x - \\bar{x})^2\\)
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Remember to consider which formula applies to samples.
4Question 4.
True or False: Standard deviation can be negative.
- True
- False
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Think about what standard deviation represents in terms of distance.
Question 5.
Analyze a dataset consisting of five test scores: 85, 87, 93, 75, 80. Calculate both variance and standard deviation, discussing what these values imply about the consistency of performance.
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Carefully compute each score's deviation and square it before averaging.
Question 6.
Given the marks distribution in a competition across various teams: 0-20 (4 teams), 21-40 (5 teams), calculate the standard deviation using the grouped data method. Discuss how this helps in assessing team performance consistency.
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Make sure to compute frequencies accurately and find class midpoints!

4 more questions in this section. Enroll free to practise them all.