# Find the Upper or Third Quartile 20 , 23 , 28 , 14 , 13 , 24 , 18 , 11 20 , 23 , 28 , 14 , 13 , 24 , 18 , 11
There are 8 observations, so the median is the mean of the two middle numbers of the arranged set of data. Splitting the observations either side of the median gives two groups of observations. The median of the lower half of data is the lower or first quartile. The median of the upper half of data is the upper or third quartile.
The median of the lower half of data is the lower or first quartile
The median of the upper half of data is the upper or third quartile
Arrange the terms in ascending order.
11,13,14,18,20,23,24,28
Find the median of 11,13,14,18,20,23,24,28.
The median is the middle term in the arranged data set. In the case of an even number of terms, the median is the average of the two middle terms.
18+202
Remove parentheses.
18+202
Cancel the common factor of 18+20 and 2.
Factor 2 out of 18.
2⋅9+202
Factor 2 out of 20.
2⋅9+2⋅102
Factor 2 out of 2⋅9+2⋅10.
2⋅(9+10)2
Cancel the common factors.
Factor 2 out of 2.
2⋅(9+10)2(1)
Cancel the common factor.
2⋅(9+10)2⋅1
Rewrite the expression.
9+101
Divide 9+10 by 1.
9+10
9+10
9+10
19
Convert the median 19 to decimal.
19
19
The upper half of data is the set above the median.
20,23,24,28
The median for the upper half of data 20,23,24,28 is the upper or third quartile. In this case, the third quartile is 23.5.
The median is the middle term in the arranged data set. In the case of an even number of terms, the median is the average of the two middle terms.
23+242
Remove parentheses.
23+242
472
Convert the median 472 to decimal.
23.5
23.5
Find the Upper or Third Quartile 20 , 23 , 28 , 14 , 13 , 24 , 18 , 11     