x is the number od doubling periods ( which is given as every 7 years)
28 years / 7 = 4 doubling periods in 28 years
so x = 4
so you now have:
f(x) = 8000 * 2^4
2^4 = 16
so 8000 * 16 = $128,000 would be the answer
Please give brainliest.
