Its a exponential function on a table

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

Answers4.) -1/205.) -1/406.) -55/127.) -3/4