Math Problem Statement

Consider the following data:

12,10,13,3,4,6

Step 1 of 3: Calculate the value of the sample variance. Round your answer to one decimal place.

Solution

To calculate the sample variance, we follow these steps:

Step 1: Find the mean (average) of the data.

The data points are: 12,10,13,3,4,612, 10, 13, 3, 4, 6.

Mean=12+10+13+3+4+66=486=8\text{Mean} = \frac{12 + 10 + 13 + 3 + 4 + 6}{6} = \frac{48}{6} = 8

Step 2: Calculate the squared differences from the mean.

For each data point xix_i, we compute (ximean)2(x_i - \text{mean})^2:

(128)2=16,(108)2=4,(138)2=25(12 - 8)^2 = 16, \quad (10 - 8)^2 = 4, \quad (13 - 8)^2 = 25 (38)2=25,(48)2=16,(68)2=4(3 - 8)^2 = 25, \quad (4 - 8)^2 = 16, \quad (6 - 8)^2 = 4

Step 3: Find the sum of the squared differences.

16+4+25+25+16+4=9016 + 4 + 25 + 25 + 16 + 4 = 90

Step 4: Divide the sum by n1n - 1 (where n=6n = 6).

Sample Variance=9061=905=18\text{Sample Variance} = \frac{90}{6 - 1} = \frac{90}{5} = 18

Thus, the sample variance is 18.0.

Would you like further details or have any questions?


Here are five questions for further exploration:

  1. How would the sample variance change if an additional data point is added?
  2. What is the standard deviation of the given data?
  3. How is sample variance different from population variance?
  4. Can you calculate the mean absolute deviation of the data?
  5. How do outliers affect the sample variance?

Tip: Sample variance is sensitive to extreme values (outliers), so be cautious when interpreting it for datasets with significant outliers.

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Math Problem Analysis

Mathematical Concepts

Statistics
Variance
Mean
Standard Deviation

Formulas

Sample Variance: S^2 = Σ(x_i - x̄)^2 / (n - 1)
Mean: x̄ = Σx_i / n

Theorems

Sample Variance Theorem
Properties of Variance

Suitable Grade Level

Grades 9-12