The standard deviation is a measure that indicates the extent to which the peaks and troughs of a wave differ on average from the mean voltage. A large standard deviation is a measure of large amplitude waves, i.e., on average the peaks and troughs differ by a large extent from the mean voltage.
The weighted average formula is used to calculate the average value of a particular set of numbers with different levels of relevance. The relevance of each number is called its weight. The weights should be represented as a percentage of the total relevancy. Therefore, all weights should be equal to 100%, or 1.
There are two main cases where you will generally use a weighted average instead of a traditional average. The first is when you want to calculate an average that is based on different percentage values for several categories. One example might be the calculation of a course grade mentioned earlier.he student has earned the following scores for each category: tests-83, final exam-75, quizzes-90, homework-100. We need to calculate the student's overall grade. To calculate a weighted average with percentages, each category value must first be multiplied by its percentage.