Mean, median, and mode can be defined as three kinds of "averages". If the data are numbers:
• Mean - when you sum all the numbers and then divide by the number of numbers
• Median - the "middle" value in the list of numbers ( numbers sholud be listed in numerical order from smallest to largest)
• Mode - the value that occurs most often.
If the distribution is normal (symmetric histogram) then mean, median and mode are equal.
If histogram is skewed-to-the-left (negatively skewed histogram) the mean is the smallest, the mode is the biggest, and the median is between the mean and the mode.
If histogram is skewed-to-the-right (positively skewed histogram) the mean is the biggest, the mode is the smallest, and the median is between the mean and the mode.