Give a 99.5% confidence interval, for $\displaystyle \mu_{{1}}-\mu_{{2}}$ given the following information.
$\displaystyle {n}_{{1}}={20}$, $\displaystyle \overline{{x}}_{{1}}={2.74}$, $\displaystyle {s}_{{1}}={0.31}$
$\displaystyle {n}_{{2}}={40}$, $\displaystyle \overline{{x}}_{{2}}={2.53}$, $\displaystyle {s}_{{2}}={0.89}$

Rounded both solutions to 2 decimal places.
$\displaystyle \pm$