Ten observations 5,9,14,15,x+1,2x−13,28,30,32,34 are written in ascending order. The median of the data is 24. Find the value of x.
- A20
- B19
- C21
- D16
Solution & Step-by-step Explanation
The total count of data observations given is n=10, which is an even number.
For an even number of observations sorted in ascending sequence, the median is calculated as the average of the two middle terms, located at positions
2
n
and (
2
n
+1):
Middle terms positions=
2
10
=5
th
termand5+1=6
th
term
From the sorted list:
5
th
term=x+1
6
th
term=2x−13
Formulating the median equation:
Median=
2
(x+1)+(2x−13)
=24
2
3x−12
=24
3x−12=48
3x=60⟹x=20
For an even number of observations sorted in ascending sequence, the median is calculated as the average of the two middle terms, located at positions
2
n
and (
2
n
+1):
Middle terms positions=
2
10
=5
th
termand5+1=6
th
term
From the sorted list:
5
th
term=x+1
6
th
term=2x−13
Formulating the median equation:
Median=
2
(x+1)+(2x−13)
=24
2
3x−12
=24
3x−12=48
3x=60⟹x=20