Numbers 50, 42, 35, 2x + 10, 2x – 8, 12, 11, 8 are written in descending order and their median is 25, find x.
Question:
Numbers 50, 42, 35, 2x + 10, 2x – 8, 12, 11, 8 are written in descending order and their median is 25, find x.
Solution:
Given the number of observation, n = 8
$\therefore$ Median $=\frac{\overline{\overline{2}}^{\text {th }} \text { value }+\left(\frac{\mathrm{n}}{2}+1\right)^{\text {th }} \text { value }}{2}$
$=\frac{\frac{8^{\text {th }}}{2} \text { value }+\left(\frac{8}{2}+1\right)^{\text {th }} \text { value }}{2}$
$=\frac{4^{\text {th }} \text { value }+5^{\text {th }} \text { value }}{2}$
$=\frac{2 x+10+2 x-8}{2}$
= 2x + 1
Given Median = 25
∴ 2x + 1 = 25
⇒ 2x = 24
⇒ x = 12