Your question is Mean and Variance of Data. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
You are given a small numeric dataset and want to summarize its center and spread before using it in downstream analysis. A simple example is the values 4, 8, 6, 5, 3, 7, 9.
Write a function to calculate the mean and variance of a dataset.