1) the mode is the number that repeats the most in a given set of numbers, so the answer would be c, 18
2) the median is b, 16 (if you put the numbers in chronological order, there are two middle numbers, to get the median you have to average those two numbers)
3) the mean is d, 14.25 (add all the numbers up and divide by the amount of numbers that you have [if you have 5 numbers, you divide by 5])
4) the median is 2.3
5) the mean is 18
hope this helps!
