Question 475516
  <pre><font face = "Tohoma" size = 4 color = "indigo"><b> 
Hi,
what grade must a student make on his fourth test in order to have an average of 90 
if his other grades are 86 85 94?
Let x represent the grade on the 4th test
(86 +85 + 94 + x)/4 = 90
(86 +85 + 94 + x)= 360         
               x = 360-265
               x = 95