This is a geometric sequence problem.
You have a sequence of;
2/3, 2, 6, 18, 54
Their common ratio is t1/t0 = 2/(2/3) = 3
Formula for G.P n terms is denoted by
ar^(n-1) = nth term
Where;
a - first term
r - common ratio
n - nth term in the sequence
So the exponential formula is basically that.
Example
To find the 3rd term which is 6
ar^(n-1) = (2/3)(3)^(3-1)
-> (2/3)(3)²
-> (2/3)(9)
-> (2)(3)
-> 6
