a factory makes memory cards in batches of 4000. for testing purposes, 150 memory cards are selected at…

a factory makes memory cards in batches of 4000. for testing purposes, 150 memory cards are selected at random from each batch. of this sample, 9 memory cards are found to be broken. about how many memory cards in the batch are likely to be broken in all?\na 16,667\nb 240\nc 444\nd 10
Answer
Explanation:
Step1: Set up proportion
Let $x$ be the number of broken memory - cards in the batch. The proportion is $\frac{9}{150}=\frac{x}{4000}$.
Step2: Cross - multiply
$150x = 9\times4000$.
Step3: Solve for $x$
$x=\frac{9\times4000}{150}=\frac{36000}{150}=240$.
Answer:
B. 240