Standard Deviation Table 3131Cb
1. Let's restate the problem: Calculate the sample standard deviation of the data set $\{2,4,4,4,5,5,7,9\}$ using a table.
2. Recall the formula for sample standard deviation:
$$s = \sqrt{\frac{1}{n-1} \sum_{i=1}^n (x_i - \bar{x})^2}$$
where $n$ is the sample size and $\bar{x}$ is the sample mean.
3. First, calculate the mean:
$$\bar{x} = \frac{2+4+4+4+5+5+7+9}{8} = 5$$
4. Now, create a table with columns: Data point $x_i$, Deviation $(x_i - \bar{x})$, Squared deviation $(x_i - \bar{x})^2$.
| $x_i$ | $x_i - \bar{x}$ | $(x_i - \bar{x})^2$ |
|-------|-----------------|---------------------|
| 2 | 2 - 5 = -3 | $(-3)^2 = 9$ |
| 4 | 4 - 5 = -1 | $(-1)^2 = 1$ |
| 4 | -1 | 1 |
| 4 | -1 | 1 |
| 5 | 0 | 0 |
| 5 | 0 | 0 |
| 7 | 7 - 5 = 2 | $2^2 = 4$ |
| 9 | 9 - 5 = 4 | $4^2 = 16$ |
5. Sum the squared deviations:
$$9 + 1 + 1 + 1 + 0 + 0 + 4 + 16 = 32$$
6. Calculate the sample variance:
$$s^2 = \frac{32}{8 - 1} = \frac{32}{7} \approx 4.57$$
7. Finally, calculate the sample standard deviation:
$$s = \sqrt{4.57} \approx 2.14$$
Final answer: The sample standard deviation of the data set is approximately $2.14$.