The mean is
\(\displaystyle\frac{{Σ{x}}}{{n}}\)

a)Here the mean is \(\displaystyle\frac{{85}}{{10}}={8.5}\)

b)Here the mean is \(\displaystyle\frac{{400}}{{16}}={25}\)

c)Here the mean is \(\displaystyle\frac{{35}}{{45}}=\frac{{7}}{{9}}\)

d)Here the mean is \(\displaystyle\frac{{242}}{{18}}=\frac{{121}}{{9}}\)

a)Here the mean is \(\displaystyle\frac{{85}}{{10}}={8.5}\)

b)Here the mean is \(\displaystyle\frac{{400}}{{16}}={25}\)

c)Here the mean is \(\displaystyle\frac{{35}}{{45}}=\frac{{7}}{{9}}\)

d)Here the mean is \(\displaystyle\frac{{242}}{{18}}=\frac{{121}}{{9}}\)