What is this series written in sigma notation 2.5 + 2.5(1.2)+2.5(1.2)^2+...+2.5(1.2)^87

Step-by-step explanation:

n

Σ (2.5)*(1.2)ⁿ

i = 1

in problems involving proportions, we can use cross products to test whether two ratios are equal and form a proportion. to find the cross products of a proportion, we multiply the outer terms, called the extremes, and the middle terms, called the means.

hope it

answer: the answer is ann