The simple moving average sums the prices (you can choose from the closing price, the VWAP time-weighted price or the high/low/close average price) for a specific number of data points and divides by that number. The calculation for a 3-bar simple moving average is:

(price_1) + (price_2) + (price_3) divided by 3

To apply a Simple Moving Average

- From within a chart, from the Edit menu select Studies.
- Choose Simple Moving Avg. and Add the study.
- Complete parameters as necessary.