Final answer:
To calculate standard deviation, find the mean, calculate each data point's deviation from the mean, square these values, average them to find the variance, and then take the square root to get standard deviation. Use a calculator's statistical functions to simplify the process.
Step-by-step explanation:
To calculate the standard deviation for stock A, you need to follow several steps which involve using a calculator or computer. First, you would find the mean (average) of the stock prices. Once the mean is calculated, you use that value to find the deviation of each stock price from the mean and square these deviations. Next, if working with a sample, you average these squared deviations to find the variance; for a population, you would divide by the number of data points. The standard deviation is the square root of the variance.
If you are using a graphing calculator like the TI-83, 83+, or 84+, select either the sample standard deviation (sx) or the population standard deviation (ox) from the summary statistics to get your standard deviation. Using the formula x = mean + (#ofSTDEVs)(standard deviation), you can then find the value that is one or two standard deviations above or below the mean, which helps in understanding the dispersion of data.