To find the mean add up all the numbers and divide by how many numbers there are:
(9+9+14+7+12+8+11+19+15+11)/10
mean= 11.5
To find the median you have to arrange to least to greatest order and cross out all of the numbers left to right until you get the median :
7,8,9,9,11,11,12,14, 15,19
Median= 11 (Middle number/value)
To get the range, you have to find the difference between the highest to the lowest value :
range= 12
Mode (how often a number repeats) :
Mode= 11
IQR(Difference between the highest value (Q3) and lowest value (Q1) :
14-9= 5
Hope this helps.