Median is the midpoint of the data array. The symbol that i usually see median is MD.
Step 1: Arrange the data in order. (least to most)
Step 2: Select the middle point.
As you can see, there are 20 data values, the middle would be the average between data value 10 and 11.
(8+8)/2 = 8
8 is the MD
Procedure:
Finding a Data Value Correspoding to a Given Percentile:
Step 1: Arrange the date in order from lowest to highest.
Step 2: Substitute in the formula:
c = (n*p)/100
where n = total number of values
p = percentile
Step 3A If c is not a whole number, round up to the next whole number. Starting at the lowest value, count over to the number that corresponds to the rounded-up value.
Step 3B: If c is a whole number, use the value halfway between c and c +1 when counting up from the lowest value.
Answer:
Step 1: Done
Step 2: c = (20*30)/100 = 6
6 is a whole number so we need to use Step 3B instead of Step 3A.
Step 3B: Use the number between values 6 and 7.... which is 5.5 Value 6 is 5 and Value 7 is 6. (5+6)/2 = 5.5
5.5 is the 30th percentile.