Answer
The cost of mailing a letter that weighs 1.8 ounces is $0.71$ dollars.
Work Step by Step
The cost of mailing a letter of weight 1.8 ounces is the value of the function at a weight of 1.8 ounces. The cost of mailing a letter that weighs 1.8 ounces can be calculated as below:
It can be observed from the graph that the value of the function remains constant from $x=2$ to $x=3$.
So the value of the function at $x=1.8$ is as below:
$f\left( 1.8 \right)=0.71$
Hence, the cost of mailing a letter that weighs 1.8 ounces is $0.71$ dollars.
