Question

What is the value of the fourth term in a geometric sequence for which a1=10 and r =0.5

Answer 1

Answer: 1.25

Explanation:

The explicit formula for the sequence is
`a_(n)=10(0.5)^(n-1)`

Substituting in n=4,

`a_(4)=10(0.5)^(4-1)=\boxed{1.25}`