How do I solve these math problems?

Measures of central tendency in the field of Statistics are mean, mode, and median. Since mean is really the average of data it will change a lot when you have some extreme value. Mode is most repeated value, so it will stay unaffected. Median is the middle value of your data (organized from smallest to largest), so it really does not matter, what values are at the end or begging (where the outliers are found).