# Creating an aggregate for class average for a test

**URL:** <https://cl.desmos.com/t/creating-an-aggregate-for-class-average-for-a-test/5068>\
**Category:** Questions\
**Tags:** aggregate\
**Created:** [August 3, 2023, 11:48pm UTC](https://cl.desmos.com/t/creating-an-aggregate-for-class-average-for-a-test/5068 "2023-08-03T23:48:10Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Micah\_Baldree](https://yyz1.discourse-cdn.com/flex031/user_avatar/cl.desmos.com/micah_baldree/32/387_2.png) [@Micah\_Baldree](https://cl.desmos.com/u/Micah_Baldree)\
**Post date:** [August 3, 2023, 11:48pm UTC](https://cl.desmos.com/t/creating-an-aggregate-for-class-average-for-a-test/5068/1 "2023-08-03T23:48:10Z")

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> **[Geometry Diagnostic • Activity by Micah Baldree](https://classroom.amplify.com/activity/64cc21caa786ad8c49456bf2)**
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> by Micah Baldree

This is my diagnostic I am giving at the beginning of the year. I have it set up to grade each question on the last slide, and then it also shows the class average for each question. I dont know why, but I am just blanking on how to also create a way to show the class average for the overall test too. I would like to display that number on the last slide under the individual student grade. Any thoughts on how to best tackle that?

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**Author:** ![ianmcmeek](https://yyz1.discourse-cdn.com/flex031/user_avatar/cl.desmos.com/ianmcmeek/32/3966_2.png) [@ianmcmeek](https://cl.desmos.com/u/ianmcmeek)\
**Post date:** [August 7, 2023, 3:13pm UTC](https://cl.desmos.com/t/creating-an-aggregate-for-class-average-for-a-test/5068/2 "2023-08-07T15:13:31Z")

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Hi Micah,

It looks like you already have one solution in place that averages a list of per problem class averages. I made your calculation visible in [this copy](https://teacher.desmos.com/activitybuilder/custom/64d100a28db4eb35fb42a18a) by adjusting the `hidden` sinks of the two notes at the top of the right column on your last screen. I didn’t test it out beyond the Student Preview, but I believe your approach will work great. If you are curious about other ways to achieve the same result, you could also aggregate your `collection` variable that stores a student’s total score. I hope that helps!

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**Author:** ![Micah\_Baldree](https://yyz1.discourse-cdn.com/flex031/user_avatar/cl.desmos.com/micah_baldree/32/387_2.png) [@Micah\_Baldree](https://cl.desmos.com/u/Micah_Baldree)\
**Post date:** [August 7, 2023, 5:17pm UTC](https://cl.desmos.com/t/creating-an-aggregate-for-class-average-for-a-test/5068/3 "2023-08-07T17:17:58Z")

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Thank you! I was thinking about the list, but I just got lost in my own code and needed fresh eyes. I appreciate it!