A normal distribution curve is a statistical function that describes how data behaves around any given mean. Also known as a Gaussian distribution or bell curve, a normal distribution curve allows statisticians to analyse data and make predictions. Graphing a normal distribution curve is a frequent activity in any elementary statistics class. Microsoft's Excel 2007 can make this activity easy for you by providing you with dynamic graphing tools that can create professional-looking graphs from your data.

Open a new worksheet in Excel.

Fill in your x-values in column 1, starting at cell A1. For example, if you want your x-values to be from -10 to 10, write "-10" in cell A1, "-9.5" in cell A2, and "-9" in cell A3, all without quotes. Continue down the column until you have entered all of your values through to cell A41.

Enter "=NORMDIST(A1,0,1,0)" without quotes into cell B2. This formula is for the standard normal distribution, with a mean of 0 and a standard deviation of 1. You can enter any mean or standard deviation into this formula. For example, if you want a mean of 10 and a standard deviation of 2, enter "=NORMDIST(A1,10,2,0)" without quotes .

Highlight the two columns by left clicking on cell A1 and dragging your cursor down to cell B41.

Choose "Insert | Scatter| Scatter with Smooth Lines and Markers."

#### Tip

The more x-values you put in, the more your normal distribution will look like a bell curve. For example, try increments of 0.1 instead of 0.5. Instead of manually entering all of your values, use Excel's fill tool to fill in cells. For example, to fill in the x-values, write "-10" in cell A1, "-9" in cell A2, highlight both cells and drag the fill tool to cell A41.

#### Tips and warnings

- The more x-values you put in, the more your normal distribution will look like a bell curve. For example, try increments of 0.1 instead of 0.5.
- Instead of manually entering all of your values, use Excel's fill tool to fill in cells. For example, to fill in the x-values, write "-10" in cell A1, "-9" in cell A2, highlight both cells and drag the fill tool to cell A41.