In: Math
Find the median, the lower half and the upper half of the history 108 test scores 10,16,14,22,21,13,15,14,10,18,19,8,16,12,18,11,9,10,15,10,21,14,18,19,1819,3,25,18,13,1,16,9,14,821,13,14,18,16,5,11,17,14,12,16,18,16,18,17,10,12,19,9,3,15,17
The median is the middle number in a sorted list of numbers. So, to find the median, we need to place the numbers in value order and find the middle number.
Ordering the data from least to greatest, we get:
1 3 3 5 8 9 9 9 10 10 10 10 10 11 11 12 12 12 13 13 13 14 14 14 14 14 14 15 15 15 16 16 16 16 16 16 17 17 17 18 18 18 18 18 18 18 19 19 19 21 21 22 25 821 1819
So, the median is 15 .
The first quartile (or lower quartile or 25th percentile) is the median of the bottom half of the numbers. So, to find the first quartile, we need to place the numbers in value order and find the bottom half.
1 3 3 5 8 9 9 9 10 10 10 10 10 11 11 12 12 12 13 13 13 14 14 14 14 14 14 15 15 15 16 16 16 16 16 16 17 17 17 18 18 18 18 18 18 18 19 19 19 21 21 22 25 821 1819
So, the bottom half is
1 3 3 5 8 9 9 9 10 10 10 10 10 11 11 12 12 12 13 13 13 14 14 14 14 14 14
The median of these numbers is 11.
The third quartile (or upper quartile or 75th percentile) is the median of the upper half of the numbers. So, to find the third quartile, we need to place the numbers in value order and find the upper half.
1 3 3 5 8 9 9 9 10 10 10 10 10 11 11 12 12 12 13 13 13 14 14 14 14 14 14 15 15 15 16 16 16 16 16 16 17 17 17 18 18 18 18 18 18 18 19 19 19 21 21 22 25 821 1819
So, the upper half is
15 15 16 16 16 16 16 16 17 17 17 18 18 18 18 18 18 18 19 19 19 21 21 22 25 821 1819
The median of these numbers is 18.