Basic Sample Statistics and Parameters
First, we'll discuss the basic concepts of sample statistics and population parameters. Then, we'll talk about the degree of freedom, which is the number of independent pieces of information that a point estimate is based on. Finally, we will talk about variance, which depends on the degrees of freedom.
Degrees of Freedom
- There are 10 independent pieces of information, so there are 10 degrees of freedom.
- The degrees of freedom for an estimate is equal to the number of values minus the number of parameters estimated en route to the estimate in question. You have 15 values in your sample, and you need to estimate one parameter, the mean, in order to find the standard deviation. 15 - 1 = 14.
- 2 degrees of freedom gives the least information. It had the smallest sample used to compute the statistic and is therefore the most likely to be a poor representation of the population parameter.