Answer:
a(9) = 150*(0.4)^8 = 0.098304
Explanation:
This is a geometric sequence, because each new term is 0.4 times the previous term.
The general formula for a geometric sequence is a(n) = a(1)*r^(n - 1). Here, with a(1) = 150 and r = 0.4, we have:
a(n) = 150*(0.4)^(n - 1), and so
a(9) = 150*(0.4)^8 = 0.098304