Yet there is considerable opposition to the use of genetically modified plants for food production and other uses. Genetic engineering offers a time-saving method for producing larger, higher-quality crops with less effort and expense. You are a tomato farmer whose crops are threatened by a persistent species of beetle. 2  Each year, you spend large sums of money for pesticides to protect your crops.
To calculate the variance follow these steps: 1  Work out the Mean (the simple average of the numbers). 2  Then for each number: subtract the Mean and square the result (the squared difference). 3  Then work out the average of those squared differences.
The Excel STDEV function calculates the sample standard deviation of a supplied set of values. The format of the function is: STDEV(number1, [number2] , ... ). where the arguments, number1, [number2] , etc, are between 1 and 255 numeric values, arrays of values, or references to cells containing numbers.f you are calculating the standard deviation of an. population, you need to use the Stdevp function or the Stdev.P function. See the page on Standard Deviation in Excel for a comparison of the different Excel standard deviation functions.