Calculating $\overline{X}$ and S

 

1. [STAT]
2. Arrow right to [CALC].
3. [1-Var Stats] should already be highlighted. Press [Enter]
4. Input [2nd] [L1] (or wherever your data is stored)
5. [ENTER]. The average and SD are in $\overline{x}$ and Sx, repectively. The output $\sigma x$ is the SD formula in Equation ( 3.2) with the denominator n-1 replaced by n .