How can I average numbers from the database?

[Serhii Kulibaba]

Could you show us screenshots with that code in the success event and it's response?

[Ellen Schlechter]

Here is the code: https://d2r1vs3d9006ap.cloudfront.net...

Here is the result:
https://d2r1vs3d9006ap.cloudfront.net...

[Serhii Kulibaba]

Please use a JS below there to check the service response to be sure there are correct data:
prealert(JSON.stringify(data));/pre

Please here an example how to calculate average sum: http://stackoverflow.com/questions/10...

values of your array "grades" might be not a number, so just add a parseInt or parseFloat methods here

[Ellen Schlechter]

I tried as you suggested, but the end result didn't change. Still comes back as NaN.

[Serhii Kulibaba]

What values does you variable "grades" have? it seems it has wrong values... Could you send us it's value?

[Ellen Schlechter]

Grades contains the values from the LSV 'average weight' that are mapped in this same service. The values are numbers and if you look at this screenshot, the pink is what the console logs as in that variable. https://d2r1vs3d9006ap.cloudfront.net...

This is how it looks in the database

[Ellen Schlechter]

Do you have an update here?

[Serhii Kulibaba]

There are empty values, which are not numbers. To prevent NaN error, please check these values before use them in the average value calculation.

Please change JS code:
pretotal += parseFloat(grades);/pre
to:
pretotal += parseFloat(grades || 0);/pre

[Ellen Schlechter]

Switching out those lines of code didn't change anything. I still get the NaN error.

[Serhii Kulibaba]

Please send us a result of prealert(JSON.stringify(grades));/pre (screenshot).