Answer: $22.12
Step-by-step explanation:
I just did the compound interest formula which is
starting amount * (1. interst rate) ^ number of years
example if you have 100$ and you want to know how much it is worth if it appretiates by 7% of a period of 20 years it would look something like this;
100 * (1.10) ^20 = 672.74$
but since you have to figure out what it was in 2008 which was exactly half way in the period you divide the exponent by half so your formula should be;
I know the answer is right because I asked my teacher and it's correct.
REAL EXAMPLE: 18 * (1.51) ^.5 = 22.12$
