In: Advanced Math
Find the common ratio for the geometric sequence 2.5, 5, 10, 20, …
Consider the geometric sequence,
2.5, 5, 10, 20, …
Compute the common ratio of given geometric sequence by find the ratio of second term to the first term.
r = a2 ÷ a1
= 5 ÷ 2.5
= 2
Therefore, common ratio of given geometric sequence is r = 2.