Respuesta :

 the correct answer is 83.

yyyyyeeeeeeaaaahhhhhh bbbbooooiii
hollymoppelt
the equation you would use is 
mean= Test1+test2+test3+test4+test5+Test6+x/Total number of tests

so 83=89+78+69+81+89+90+X/7
First mutiple both sides by 7 so 
581=496+X
you then substract the 496 and get 85
so she would need a 85 on the 7th test