Mean 'calculated average' - total of samples divided by number of samples. By definition 50% of sample are above the Mean, 50% below.
Median the value in the center position when sample is ranked sequentially. This can be distorted by residual (outlier values at the extremes)
Mode the most frequently occurring value. This can be distorted by residuals.
Average here refers to the MEAN.
Where did you go to school?