Microsoft Excel has a wealth of statistical tools you can use in probability and statistics, including formulas to calculate a standard deviation.  The standard deviation is represented by the lowercase sigma (σ) symbol, and shows how much dispersion, or variation, exists in the data from the mean. The larger the standard deviation, the more spread out the data. Computing a standard deviation by hand is complicated and prone to errors. To calculate a standard deviation in Excel, you must first enter your data.
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The Texas Instruments TI-89 Titanium Graphing Calculator is a powerful graphing calculator that allows you to perform many statistical calculations. It will last you through AP statistics, elementary statistics and beyond. If you end up taking any more math classes, the TI-89 Titanium is the calculator to have for engineering and the sciences. Finding the variance and standard deviation on a TI-89 calculator is as easy as entering a few numbers and hitting a couple of keys. These instructions are for the TI-89 Titanium Graphing Calculator. Instructions for older models may differ slightly.
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There are a few ways to find the area under a normal distribution curve between 0 and any z-score using a z-table. Once you know how to read the table, finding the area only takes seconds!

If you are looking for other variations (finding the area for one tail, or between two z-scores, see this normal distribution curve index).

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Most textbooks in elementary statistics will ask you to finding the standard deviation in the binomial probability distibution chapter. This can be a challenge, because the variance and standard deviation formulas are daunting when you first look at them. This how to will tell you how to find a standard deviation for a binomial distribution in just a few steps.

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