Grade 12 Math: Variance Worksheet
A comprehensive worksheet for Grade 12 students covering the calculation and interpretation of variance in probability and statistics.
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Grade 12 Math: Variance Worksheet
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Read each question carefully and provide your answers in the spaces provided. Show all your work for calculations.
1. Define variance in your own words and explain what it measures in a dataset.
2. Which of the following is NOT a characteristic of variance?
It is always non-negative.
Its units are the square of the original data units.
It is easily interpretable in the original units of measurement.
A variance of zero means all data points are identical.
3. The square root of the variance is called the .
4. When calculating the sample variance, we divide by instead of N.
5. A set of student test scores is: 85, 90, 78, 92, 88. Calculate the variance for this sample.
6. A higher variance indicates that data points are generally closer to the mean.
True
False
7. Two investment portfolios, A and B, have the following annual returns over five years:
Portfolio A: 10%, 12%, 8%, 15%, 10%
Portfolio B: 9%, 11%, 10%, 10%, 10%
Calculate the variance for each portfolio's returns and determine which portfolio is more consistent.