The first term of a geometric sequence is 40, and the common ratio is 0.5. What is the 5th term of the sequence?

1 Answer

T_5 = 2.5

Explanation:

The n^(th) term of a geometric progression can be determined by using the formula:

color(blue)(T_n = ar^(n-1))
where: a = first term and r = common ratio

Substitute the given values of first term and common ratio into the formula:

T_n = ar^(n-1)
T_5 = (40)(0.5)^(5-1)
T_5 = (40)(0.5)^(4)
T_5 = (40)(0.0625)
T_5 = 2.5