The average of numbers is equal to sum of values to number of values.
Determine the average value of observations.
[tex]\begin{gathered} a=\frac{-\frac{2}{5}+\frac{7}{10}+\frac{1}{2}-\frac{1}{5}}{4} \\ =\frac{\frac{-4+7+5-2}{10}}{4} \\ =\frac{\frac{6}{10}}{4} \\ =\frac{3}{20} \end{gathered}[/tex]So average value of the numbers is 3/20.
