# What is the best formula for calculating average based on count?

I would like to calculate an average of the series based on the count.

Say, for example,

Series 1 (10 values): 5, 1, 2, 3, 4, 5, 4, 1, 2, 3

Average: 30 / 10 = 3

Series 2 (2 values): 3, 4

Average: 7 / 2 = 3.5

Series 2 has the higher average than series 1 but series attempted 10 times which is more than series 2 (2 times).

I need to find a formula to calculate the average based on the counts to make sure the values are perfectly averaged. Can anyone help me achieve this?

• I agree. I quoted what I actually tried in the question itself. Nov 25 '18 at 13:26
• The problem is that you want an answer for a question that you have not given. What do you mean with "perfectly averaged"? What I guess is that your series' come from some kind of measurement (like school grades) and maybe you want to take into account that having an average score of 3.4 over 10 grades is more reliable than one of 3.5 over just 2 grades. But all of this information needs to come from you, there is no magical formula that will take that into account that is generally applicable. Nov 25 '18 at 16:15
• @Ingix What I need to do, then? Nov 27 '18 at 13:11
• Describe what you want in your terms, and try not to use phrases like "perfectly averaged", which are not well defined. Include the background of the question (as I guessed at). Make a new question for this. Nov 27 '18 at 13:16