#### Answer

a) 39.07 b) 27.67 c) 27.11 There are not big differences between the last 2 means, but they differ and it seems that the more they are trimmed, the more they decrease. The first mean, containing the outlier is a lot bigger than the other 2.

#### Work Step by Step

Mean: sum of data divided by number of data. a)Mean: $\frac{22.13+27.2+...+31.3+22.44}{40}=39.07.$ b) $Mean_{10\%}$: $\frac{20.37+20.85+...+37.48+39.98}{32}=27.67.$ c)$Mean_{20\%}$: $\frac{22.44+23.5+...+33.11+33.68}{24}=27.11.$ There are not big differences between the last 2 means, but they differ and it seems that the more they are trimmed, the more they decrease. The first mean, containing the outlier is a lot bigger than the other 2.