I have 5 marbles numbered 1 through 5 in a bag.  Suppose I take out two different marbles at random.  What is the expected value of the sum of the numbers on the marbles?
Question:
I have 5 marbles numbered 1 through 5 in a bag.  Suppose I take out two different marbles at random.  What is the expected value of the sum of the numbers on the marbles?
Answer:
Let's think step by step.

user
6
I have 5 marbles numbered 1 through 5 in a bag.  Suppose I take out two different marbles at random.  What is the expected value of the sum of the numbers on the marbles?
train