We're given
(0, 144)
(1, 48)
(2, 16)
(3, 16/3)
[tex]f(x) = a*b^x\\144 = a*b^0\\144 = a\\[/tex]
now that we know a, we can find b
[tex]f(x) = 144*b^x\\48 = 144*b\\b = \frac{48}{144}\\b = \frac{1}{3}[/tex]
[tex]f(x) = 144*(\frac{1}{3})^x[/tex]
