Respuesta :

10.5, since 35 is between 30 and 40 ((30+40)/2), the mistakes that correspond with them are 9 and 12, the number in between them is 10.5 (9+12=21, 21/2 is 10.5)
9 + 13 = 21
[tex] \frac{21}{2} [/tex] = 10.5