Find the median of the data:

Numbers are 12, 17, 3, 14, 5, 8, 7, 15

Arranging the numbers in ascending order

3, 5, 7, 8, 12, 14, 15, 17

n = 8 (even)

$\therefore$ Median $=\frac{\frac{\bar{n}^{\text {th }}}{2} \text { value }+\left(\frac{n}{2}+1\right)^{\text {th }} \text { value }}{2}$

$=\frac{\frac{8}{2}^{\text {th }} \text { value }+\left(\frac{8}{2}+1\right)^{\text {th }} \text { value }}{2}$

$=\frac{4^{\text {th }} \text { value }+5^{\text {th }} \text { value }}{2}$

$=\frac{8+12}{2}$

$=\frac{20}{2}=10$