Mean: The mean is the sum of all the pieces of data divided by the number of pieces of data.
Median: The median is the middle of a distribution: half the scores are above the median and half are below the median.
Mode: The most frequently occurring score in a distribution. Please note: if there is no mode, put -1 as an answer
Mid-Point: The midpoint is calculated by adding together the highest and lowest value and dividing by 2.
Trimmed Mean: This is computed by discarding the lower and higher 20% of the scores and taking the mean of the remaining scores.