Answer
$c(t)=.3t+50$ where $t$ is the amount of plastic toys produced and $c(t)$ is the cost, in dollars, of the production of the plastic toys.
Work Step by Step
In the equation $c(t)=at+b$:
The rate of change, $a$, is $30$ cents, or $.3$ dollars for every plastic toy produced.
The initial output, $b$, is $50$ dollars for the fixed cost.
Rewrite this as $c(t)=.3t+50$.