Listed below are brain volumes $\left(\mathrm{cm}^{3}\right)$ of twins listed in Data Set 6 of Appendix B. Construct a $99 \%$ confidence interval estimate of the mean of the differences between volumes for the first-born and the second-born twins. What does the confidence interval suggest?
$$\begin{array}{|l|l|l|l|}
\hline \text { First Born } & 1005 & 1035 & 1281 & 1051 & 1034 & 1079 & 1104 & 1439 & 1029 & 1160 \\
\hline \text { Second Born } & 963 & 1027 & 1272 & 1079 & 1070 & 1173 & 1067 & 1347 & 1100 & 1204 \\
\hline
\end{array}$$