Since the interest is simple, you don't have to compound it multiple times. You just need to divide the 208 days with 365days. The calculation would be:
interest= principal * number of year * rate
interest= $18,981 * 208/365 * 9%=$973.49
D = r t
384 = 640 * t
384/640 = t
.6 = t .6 of an hour
.6 hr * 60min/1 hr = 36 minutes (just in case it needs to be in minutes)
Using how tall it is over how wide
=>tall/wide
The model 15in/1.5in
The actual x/55ft
Convert everything into the same units so 55ft to inches
There are 12in in 1ft
55ft * 12in/1ft
The ft cross out leaving in
55*12in= 660 in
So
15in/1.5in = x/660in
Now solve for x my multiplying both side by 660in
660in *15in/1.5in=x
x= 6600in tall