1. **State the problem:** We are given a sample of scores: 1, 3, 1, 1. We need to calculate the sum of squares (SS) using the computational formula, then compute the sample variance and standard deviation.
2. **Recall the formulas:**
- Sum of squares (SS) using computational formula: $$SS = \sum x_i^2 - \frac{(\sum x_i)^2}{n}$$
- Sample variance: $$s^2 = \frac{SS}{n-1}$$
- Sample standard deviation: $$s = \sqrt{s^2}$$
3. **Calculate the sums:**
- $$\sum x_i = 1 + 3 + 1 + 1 = 6$$
- $$\sum x_i^2 = 1^2 + 3^2 + 1^2 + 1^2 = 1 + 9 + 1 + 1 = 12$$
- Sample size $$n = 4$$
4. **Calculate SS:**
$$SS = 12 - \frac{6^2}{4} = 12 - \frac{36}{4} = 12 - 9 = 3$$
5. **Calculate sample variance:**
$$s^2 = \frac{SS}{n-1} = \frac{3}{4-1} = \frac{3}{3} = 1$$
6. **Calculate sample standard deviation:**
$$s = \sqrt{1} = 1$$
**Final answers:**
- Sum of squares (SS) = 3
- Sample variance = 1
- Sample standard deviation = 1
Sample Variance 0Fd889
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