Math Problem Statement

Given the variance of the set of data 3, 5, 6, 7, and 9 is 4, calculate the variance of the set of data 6, 10, 12, 14, and 18.

Solution

To solve this problem, let’s break down the information and use properties of variance.

Problem Statement

  1. We are given a set of dataTo solve this problem, let’s break down the information and use properties of variance.

Problem Statement

  1. We are given a set of 3,5,6,7,3, 5, 6, 7, and 99.
  2. The variance of this data set is 44.
  3. We are asked to find the variance of a new set of dataTo solve this problem, let’s break down the information and use properties of variance.

Problem Statement

  1. We are given a set of 3,5,6,7,3, 5, 6, 7, and 99.
  2. The variance of this data set is 44.
  3. We are asked to find the variance of a new set of 6,10,12,14,6, 10, 12, 14, and 1818.

Analysis

Notice that each element in the second set is obtained by multiplying each element in the first set by 22: 6=2×3,10=2×5,12=2×6,14=2×7,18=2×96 = 2 \times 3, \quad 10 = 2 \times 5, \quad 12 = 2 \times 6, \quad 14 = 2 \times 7, \quad 18 = 2 \times 9

Variance Scaling Property

If we multiply each element in a data set by a constant kk, the variance of the new data set becomes k2k^2 times the variance of the original data set.

Here:

  • The original variance =4= 4.
  • The scaling factor k=2k = 2, so the new variance will be: New Variance=k2×(Original Variance)=22×4=4×4=16\text{New Variance} = k^2 \times (\text{Original Variance}) = 2^2 \times 4 = 4 \times 4 = 16

Conclusion

The variance of the new data set 6,10,12,14,6, 10, 12, 14, and 1818 is 1616.

Answer

D. 16


Would you like further details on this solution, or have any questions?

Related Questions

  1. How would the variance change if each element of a data set is increased by a constant instead of multiplied?
  2. What is the relationship between standard deviation and variance when scaling a data set?
  3. How can we find the mean of the new data set based on the original data set?
  4. If the variance of a data set is zero, what does that indicate about the data points?
  5. How do we calculate the variance of a data set from scratch if not given?

Tip

Always remember that variance scales with the square of the multiplier when each data point is scaled by a constant.

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Math Problem Analysis

Mathematical Concepts

Statistics
Variance
Scaling Properties of Variance

Formulas

New Variance = k^2 * Original Variance

Theorems

Variance Scaling Property

Suitable Grade Level

Grades 10-12