(a)

Equation used by pharmacists is $\"\"$ ,

Where $\"\"$ is appropriate dosage of child(in mg), $\"\"$ is adult dosage(in mg) and $\"\"$ is age of the child (in years).

The adult dosage is $\"\"$ mg.

Substitute $\"\"$ in the pharmacists equation.

$\"\"$

Compare above equation with slope-intercept form of line equation $\"\"$ .

Here slope of the graph $\"\"$ is 8.34.

It represents change in dosage of child in mg for every 1 year.

(b)

For a newborn baby age is 0.

Substitute $\"\"$ in the pharmacists equation.

Dosage for a new born baby is

$\"\"$

The newborn baby dosage is 8.34 mg.

(a)

Slope of the graph $\"\"$ is 8.34.

Slope represents change in dosage of child in mg for every 1 year.

(b)

Dosage for a new born baby is 8.34 mg.