# Programming in Dart: Fundamentals

## Part 2: Introducing Collections & Null Safety

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In the last episode, you learned about lists. Now its time to put your new found knowledge to the test. In this challenge, I want you to create a list called grades. The grades should be 82, 76, 88, and 92. I want you store those values in the list, then calculate the average of the values. Pause the video and give it a shot.

``````const grades = [82, 76, 88, 92];
``````
``````var sum = grades[0] + grades[1] + grades[2] + grades[3];
``````
``````var average = grades / 4;
``````
``````print('the average is \$average');
``````
``````var sum = grades.first + grades[1] + grades[2] + grades[3];
``````
``````var sum = grades.first + grades[1] + grades[2] + grades.last;
``````
``````var average = sum / grades.length;
``````