The steps to prove whether a given number sequence is a geometric progression

The steps to prove whether a given number sequence is a geometric progression.

Step 1: List down any three consecutive terms. [Example: T1, T2, T3.]
Step 2: Calculate the values of T 3 T 2  and T 2 T 1  .
Step 3: If T 3 T 2 = T 2 T 1 =r  , then the number sequence is a geometric progression.

Step 4: If T 3 T 2 T 2 T 1  , then the number sequence is not a geometric progression.