Explain what central tendency and variability are. In your answer define what the mean, median, mode, variance, and standard deviation are. What is the difference between the descriptive standard deviation and the unbiased estimate of the standard deviation? When would you use the unbiased estimate?
Central tendency is to describe where the data are and variability is how spread out the data are... Variability tells on how constant the score are. The mean is the sum of all the values in a group divided by the number of the values in that group. The median is the average but of a different kind, the median in the midpoint in a set of scores, it is the half way point which is 50% the mode is the last measure of central tendency it is the precise measure of the central tendency. Variances is used as a measure of how far a set of numbers are spread out from each other and the Standard deviation represents the average amount of variability in a set of scores. The standard deviation is the square root of the variance.