Answer
(a) $c=8.34a+8.34$
The slope represents rate of change of dosage for a child according the age.
(b) $c=8.34mg$
Work Step by Step
(a) $c=0.0417D(a+1)$
if $D=200$
$c=8.34(a+1)=8.34a+8.34$
The slope is $8.34$ and it represents rate of change of dosage for a child according the age.
(b) For a newborn age is considered as $0$, so we can calculate:
$c=8.34\times0+8.34=8.34mg$
