Measures Dispersion
1. Let's start by understanding what measures of dispersion are.
Measures of dispersion describe the spread of data points in a dataset, indicating how much variability exists.
2. Common measures include range, variance, and standard deviation.
- Range is the difference between the maximum and minimum data points.
- Variance measures the average squared deviations from the mean.
- Standard deviation is the square root of variance, showing dispersion in original units.
3. To solve problems involving measures of dispersion, first calculate the mean $\mu$ using:
$$\mu = \frac{\sum x_i}{n}$$
where $x_i$ are data points and $n$ is the number of points.
4. Then calculate variance $\sigma^2$:
$$\sigma^2 = \frac{\sum (x_i - \mu)^2}{n}$$
5. Finally, find standard deviation $\sigma$:
$$\sigma = \sqrt{\sigma^2}$$
6. These steps allow you to quantify how spread out your data is, helping to interpret and compare datasets.