how to calculate average rating

Question

Sorry if I am not clear:

How would I calculate the average rating based on the MinRate and MaxRate

for example: minRate = 0 or 1 and MaxRate = 2 or 3 or 4 or 5 or 0

How would I calculate the rating?

Update End

I am implementing a 5 star rating system and my table structure has two columns: 1) MinRate 2) MaxRate

so my question is: how do calculate the average rating?

here is how I have in my 5 star rating implementation.

int[] {7, 0, 0, 8, 5}; 

This means that:

• 7 users rated the article with a 1
• 0 users rated the article with a 2
• 0 users rated the article with a 3
• 8 users rated the article with a 4
• 5 users rated the article with a 5

Answer 1

Here is some pseudo code:

double avg = 0;
for (int i = 0; i < arr.Length; i++) // arr.Length should be the same as MaxRate
{
    avg += arr[i] * (i + MinRate);
}
avg /= arr.length;