What is the value of the fourth term in a geometric sequence for which a1=15 and r=1/3

Formula: an = a1 (r) ^n-1

n = term number

a1 = first term

r = rate

Plug our values in:

n = 4

a1 = 15

r = 1/3

a4 = 15 (1/3) ^4-1

a4 = 15 (1/3) ^3

a4 = 15 (1/27)

a4 = 0.5555555556

a4 = 0.6 to the nearest tenth