The standard deviation for these four quiz scores is 2.58 points. Because calculating the standard deviation involves many steps, in most cases you have a computer calculate it for you. However, knowing how to calculate the standard deviation helps you be

Then your professor says the standard deviation of the exam was 2%; now things are actually looking really good! If the class average was 63%, 1 standard deviation to the positive would be 65% (not to cause confusion here, but 68% of the class scored betw

This figure is the standard deviation. Usually, at least 68% of all the samples will fall inside one standard deviation from the mean. Remember in our sample of test scores, the variance was 4.8. √4.8 = 2.19. The standard deviation in our sample of test