Question

What is the value of r of the geometric series? 0.8 1.3 3.0 3.2

a. 0.8
b. 1.3
c. 3.0
d. 3.2

Answer 1

b is the answer

Explanation:

Answer 2

b is the answer

Explanation:

Formula used :

Sum of the first 4 geometric series is

`s=a((1-r^4)/(1-r) )`

where a=0.8 and sum= 0.8+1.3+3.0+3.2=8.3

putting value in formula,

which give equation
`r^4-10.357r+9.375=0`

and value of r lie between (1,1.6)

therefore, r = 1.3