Question

the second term in a geometric sequence is 50. The fourth term in the same sequence is 112.5. What is the common ratio in this sequence?

Answer 1

any attempts so far?

a_n = a_1 * r^(n-1) is the geometric series formula

plugging in the "second term" 50 gives us a_n = 50 and n = 2

50 = a_1 * r^(2-1)

try writing the formula out for the "fourth term" 112.5 using this same logic

then divide the two formulas to solve for r

lmk if you are getting stuck or want to check your solution