Answer
Multiple-dose vial required = 4.5mL
Work Step by Step
We are given:
Multiple-dose vial has 200,000 units in 1mL
This means that the ratio is: $\frac{200,000}{1}$
We need to find the mL required to give 900,000 units.
Therefore,
for 1 mL = 200,000 units.
for "x" mL = 900,000 units
$= 900,000*\frac{1}{200,000}$
So, the multiple-dose vial required = 4.5mL
