Periodically, the county Water Department tests the drinking water of homeowners for contaminants such as lead and copper. The lead and copper levels in water specimens collected in 1998 for a sample of 10 residents of a subdevelopement of the county are shown below.

lead ($\mu$g/L)	copper (mg/L)
$2.5$	$0.756$
$4.8$	$0.517$
$1.3$	$0.205$
$4.3$	$0.461$
$5.8$	$0.186$
$3.2$	$0.481$
$3.5$	$0.782$
$3.4$	$0.654$
$1.2$	$0.362$
$1.1$	$0.704$

(a) $\ $ Construct a $99$% confidence interval for the mean lead level in water specimans of the subdevelopment.
$\leq \mu \leq$

(b) $\ $ Construct a $99$% confidence interval for the mean copper level in water specimans of the subdevelopment.
$\leq \mu \leq$