Question

a mixture requires 3 parts water for every 8 parts of boric acid. how much water should a medical laboratory technician add to 52 oz. of boric acid to get the necessary proportion? write your answer as a decimal.

1. 138.7 oz. of water
2. 2.2 oz. of water
3. 156 oz. of water
4. 19.5 oz. of water

Explanation:

Step1: Set up proportion

Let $x$ be the amount of water. The proportion is $\frac{3}{8}=\frac{x}{52}$.

Step2: Cross - multiply

$8x = 3\times52$.

Step3: Calculate right - hand side

$3\times52=156$, so $8x = 156$.

Step4: Solve for $x$

$x=\frac{156}{8}=19.5$.

Answer:

D. 19.5 oz. of water