Answer:
the 11th term is 0.0000488 or 4.88*10^-5.
Step-by-step explanation:
a3 = 20, a7 = 1.25
a7 = a3r^7-3
1.25 = 20r^4
r^4 = 0.0625
r = 4th root of 0.0625
r = 0.5
a3 = a1r^3-1
20 = a1(20)^2
400a1 = 20
a1 = 0.05
a11 = 0.05(0.5)^11-1 = 0.0000488 or 4.88*10^-5
