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 standard deviation calculation tells you how spread out the numbers are in your sample. To figure this out for your sample or data set, you will need to perform a few calculations first. You will need to find the mean and variance of your data before you can find the standard deviation.