Answer:
10.95 mL
Step-by-step explanation:
The volume of solution is proportional to the amount you want to administer, so you have ...
dose/(200 mg) = (1 tsp)·(4.92892 mL/tsp)/(90 mg)
Multiplying by 200 mg, we get
dose = 200·1·4.92892/90 ≈ 10.953 mL
About 10.95 mL of the solution should be administered to give a dose of 200 mg.
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Comment on the conversion factor
1 tsp = 231/768 cubic inches = 4.92892159375 mL exactly
The value is often rounded to 5 mL for cooking purposes. Using that value here would make the dose be 11.11 mL, about 3 mg of drug more than desired.
