Answer:
[tex] \boxed{ \bold{ \huge{\boxed{ \sf{(12.5 \: , \: 11.5)}}}}}[/tex]
Step-by-step explanation:
Let the points be A and B
Let A ( 13 , 15 ) be x₁ , y₁ and B ( 12 ,8 ) be x₂ , y₂
Finding the midpoint
[tex] \bold{ \boxed{ \sf{midpoint \: = (\: \frac{x1 + x2}{2} , \: \frac{y1 + y2}{2}) }}}[/tex]
[tex]\dashrightarrow{ \sf{ (\frac{13 + 12}{2} , \: \frac{15 + 8}{2} )}}[/tex]
[tex] \dashrightarrow {\sf {(\frac{25}{2} \: , \: \frac{23}{2} )}}[/tex]
[tex] \dashrightarrow{ \sf{(12.5 \: , \: 11.5)}}[/tex]
Hope I helped!
Best regards! :D