First of all, it is 2r

and it would be divide by 3.14 (pi) and then you should have the diameter. Then divide by 2 to find radius.
Answer:
$420
Step-by-step explanation:
You have the starting price of $1.99. To get the increased price, divide 1.99 by .56 (.56 is the decimal form of 56%). You would get $3.55. This is for the year 2007. So for 2008, divide 3.55 by .42. The answer is $8.45. You can check the answers by multiplying the answers you go the the percentage. Ex. 8.45* .42=3.55 (rounded)