C. $693.33. Just round. It helps. Round 2,080 to 2,100. Then whats 30% of 2,100? It's easy just think of 21 divided by 3, which equals 7. So, 700 and the closest answers to that is $693.33. That's just the easy way instead of doing the math out. And it is also common sense that B or D wouldn't be it. So your left with C or A. :)
To find the range of data, you first order the data least to greatest:
7, 12, 15
Then you subtract the smallest number from the largest:
15-7=8
The range is 8.
