Answer:
Cameron would have to pay $9,676.91 in interest alone.
Step-by-step explanation:
Hi, all we have to do is use the following formula to find the future value of this amount.

where;
Present value= 10,200
r= 0.21
t= 3.5
So, everything should look as follows

But that is the future value, in order to find the amount of interest expences Cameron would have to pay, we do as follows.

So, $9,676.91 is how much in interest alone will Cameron have paid.
Best of luck.