Question

To test the significance of regression you need to evaluate the variance (s^2). What is the variance?

Single choice.

Answer 1

Sample variance ($s^2$) is a measure of the degree to which the numbers in a list are spread out. If the numbers in a list are all close to the expected values, the variance will be small. If they are far away, the variance will be large. Sample variance is given by the equation

$$s^2=\dfrac{\sum (x_i-\bar x)^2}{n-1}$$

where n is the number of categories.

and $\bar x =\dfrac{\sum _{i=1}^nx_i}{n}$