Answer:
d) 87
Step-by-step explanation:
to solve this lets set up the equation
[tex]\frac{85+70+98+x}{4} =85\\\frac{253+x}{4} =85[/tex]
then we multiply 4 on both sides
253+x=340
and subtract 253 on both sides
x=87
to double check take the averages
(87+85+70+98)/4=85