Question

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

Answer 1

Answer:

an=1*2.5^(n-1)

=2.5^(n-1)

Step-by-step explanation:

Complete question below:

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

Solution

Point (1, 1), (2, 2.5), (3, 6.25).

a=1

ar=2.5

ar^2=6.25

From ar and ar^2

r=6.25/2.5

=2.5

r=2.5

an=ar^(n-1)

Therefore, the explicit formula is

an=1*2.5^(n-1)

=2.5^(n-1)