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 looks complicated at first, but it's really quite simple if we take it step by step. We'll start by finding the mean, or average, of all the scores. To do this, we add up all the scores and divide by the total number of scores. This gives us a mean of 10.5.