#### Answer

The baby was overmedicated by a factor of 4.9

#### Work Step by Step

We can convert $3/4~tsp$ to units of $mL$:
$3/4~tsp \times \frac{4.9~mL}{1~tsp} = 3.675~mL$
We can find the factor that the baby was overmedicated:
$\frac{3.675~mL}{0.75~mL} = 4.9$
The baby was overmedicated by a factor of 4.9, which is the conversion factor from units of $tsp$ to units of $mL$