suppose that the fixed cost for a product is $420 and the break - even quantity is 60. find the marginal…

Explanation:

Step1: Recall break - even formula

At break - even, profit $P = 0$. The profit function is $P(x)=mx - b$, where $m$ is the marginal profit, $x$ is the quantity, and $b$ is the fixed cost. When $x = 60$ (break - even quantity) and $b = 420$ and $P(60)=0$.

Step2: Substitute values into profit formula

We substitute into $P(x)=mx - b$: $0=m\times60-420$.

Step3: Solve for $m$

Add 420 to both sides of the equation: $420 = 60m$. Then divide both sides by 60: $m=\frac{420}{60}=7$.

Answer:

$7$