Ameasure of how tightly clustered a group of scores is around their mean is called the a. frequency b. standard deviation c. mode d. variability

A measure of how tightly clustered a group of scores is around their mean is called standard deviation.  Standard deviation in layman's term is simply how spread the data of scores are. It is calculated based on the square root of the variance. The correct answer is letter b

The correct answer is standard deviation, because this is a measure of how spread out the numbers are from the mean.  The smaller the standard deviation the closer together the other numbers are to the mean.