Rolling Averages and Running Totals
Time series data is noisy. A rolling average replaces each value with the average of the last few, smoothing the jumps: .rolling(3).mean(). The first values are NaN because there is not enough history yet. .cumsum() gives a running total and .pct_change() the percentage change from the previous row.
Examplepython
Quick check
Why are the first values of `rolling(3).mean()` NaN?
Your turn: write the code
Print the running total of the series.
Finish the quick check (and any code exercise) to complete this lesson, or mark it done yourself.
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