Answer:
$1,169.30
Explanation:
The answer is $1,169.30 since 621.60-600=21.60, meaning that in the past 4 years, Chelsea has gained $21.60. Then you would do 21.60/4 to find how much per year, which would get you $5.40. Then you need to find the interest rate by doing 5.40/600 since she started out with 600. 5.40/600=0.009. Then you would turn it into percentage by multiplying it by 100, to get 0.9%. Now, since she's deposited $1,100 instead, you would do 0.9*1,100, and then you would get 990, then you would have to divide it by 100 and get $9.90. That means she gains $9.90 per year. Since she'll have it for 7 years, you need to do 9.90*7=63.90. Then you would add it to 1,100 to get $1,169.30