Ten Different Families Are Tested for the Number of Litres $\text { t-test }$

Essay

Ten different families are tested for the number of litres of water a week they use before and after viewing a conservation video.Do the data suggest that the mean amount after the viewing differs from the mean amount before the viewing? Perform a paired $\text { t-test }$ at the 5% significance level. $$\begin{array} { l | l l l l l l l l l l } \text { Before } & 33 & 33 & 38 & 33 & 35 & 35 & 40 & 40 & 40 & 31 \\\hline \text { After } & 34 & 28 & 25 & 28 & 35 & 33 & 31 & 28 & 35 & 33\end{array}$$