Question

Find the geometric series whose second term is 1.5 and the fifth term is 0.1875

Answer 1

a + a r + a r^2 + a r^3 + a r^4 ....+a r^(n-1)

so
a r = 1.5
a r^4 = .1875

a = 1.5/r

(1.5/r) r^4 = .1875

r^3 = .125

r = .5
a = 1.5/.5 = 3
so

3 + 1.5 + .75 ......