Question

The data set below consists of the scores of 15 students on a quiz. for this data set, which measure of variation do you think is more appropriate, the range or the standard deviation? explain your thinking. 90 90 91 91 89 90 89 91 91 90 60 90 89 90 91

Answer 1

Standard deviation would be the best measurement of variance.  Most of the numbers are between 91 and 89 and are thus very close together and most of the data would be within that small range. The outlier of 60 makes the rance variance go from 60 to 91 when all but 6 percent of the class can be represented between 91 and 89.