Question

Lena is asked to write an explicit formula for the graphed geometric sequence.

On a coordinate plane, 3 points are plotted. The points are (1, 1), (2, 2.5), (3, 6.25).

What value, written as a decimal, should Lena use as the common ratio?

1.0
1.5
2.5
2.0

Answer 1

2.5

Reason: r = second term / first term = 2.5 / 1 = 2.5 (and 2.5 · 2.5 = 6.25 confirms it).