Answer
The final amount after 5 years of decay is approximately $280$.
Work Step by Step
RECALL:
Exponential decay is represented by the formula
$y=C(1-r)^x$
where
C = initial/original amount
r - decay rate
x = number of time intervals
The given exponential growth has:
C = 402
r = $7\%$
x = 5 years
Substitute these values into the given formula above to have:
$y=402(1-7\%)^{5}
\\y=402(1-0.07)^{5}
\\y=402(0.93^{5})
\\y=279.6667245
\\y\approx 280$
