mean = sum of scores / number of scores
mode = is the most often occurring value (if any value occurs more than once)
median - place values in numerical order
compute n = (sample size + 1)/2
if n is an integer, then median will be nth value
if n is not an integer, the median will be the average of the integer values below and above n, e.g. if n = 4.5, then median would be the average of the 4th and 5th values.