I need some help with the procedure to find the final answer.

I have: P(X>=K)=1-P(X<K)=1-[sum from i=1 until k-1] (3/8)^(i-1)*5/8

The final answer provided is (3/8)^(k-1), but I'm lost in the intermediate steps.

Any help is greatly appreciated.

- Thread starter rbriceno
- Start date