To prepare a dosage of 0.65 mg, we need to convert the strength of 500 mcg/mL to mg/mL.
First, we need to convert mcg to mg by dividing by 1000:
500 mcg ÷ 1000 = 0.5 mg
Now, we have the strength of 0.5 mg in 1.5 mL. To find the dosage of 0.65 mg, we can use a proportion:
0.5 mg / 1.5 mL = 0.65 mg / X mL
Cross multiplying, we get:
0.5 mg * X mL = 1.5 mL * 0.65 mg
0.5X = 0.975
Now, solve for X by dividing both sides of the equation by 0.5:
X = 0.975 / 0.5
X = 1.95 mL
Therefore, to prepare a dosage of 0.65 mg, you would need to administer 1.95 mL.