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.
Be able to calculate the standard deviation s from the formula for small data sets (say n â¤ 10).C. Know the basic properties of the standard deviation: â¢ s â¥0, and s = 0 only when all data values are identical. â¢ s increases as the spread about x increases.