A moving average smooths data by averaging consecutive groups of n values.
SMA(3) of [10,12,13,15] = [11.67, 13.33] — each result averages 3 consecutive points.
Common trading SMAs: 50-day (medium trend), 200-day (long-term trend).
Use this statistical calculator when you need a rigorous, reportable result — not a rough estimate. The formula is standard, but manual computation on large datasets introduces errors that undermine any subsequent analysis.
A frequent mistake is computing statistics on a dataset without checking for data entry errors, outliers, or missing values. A single transcription error in a small dataset can shift the mean and standard deviation substantially. Always verify the input data before interpreting results.
A teacher calculates the class average and standard deviation for an exam: mean 64%, SD 18%. The high SD suggests a wide spread of performance levels — indicating the class may need differentiated support rather than a single revision strategy.
The average of the last n data points, recalculated as new data arrives.