Answer:
$42.88
Explanation:
Let's create a proportion using the following setup:
cost/pounds=cost/pounds
We know that it costs $20.42 for a 10 pound turkey.
$20.42/10 pounds= cost/pounds
We don't know how much a 21 pound turkey costs, so we can say that it costs $x for a 21 pound turkey.
$20.42/ 10 pounds= $x/ 21 pounds
20.42/10=x/21
We want to find x, by getting x by itself.
x is being divided by 21. The inverse of division is multiplication. Multiply both sides by 21.
21*(20.42/10)=(x/21)*21
21* 20.42/10=x
21*2.042=x
42.882=x
Round to the nearest cent, or hundredth.
42.88=x
x= $42.88
A 21 pound turkey costs $42.88