On a test average (arithmetic mean) test score for 4 students is 85. What must be 5th student's score that average score for 5 students to be 86?	Pick one:
A) 70
B) 80
C) 90
D) 100
E) 110
(4*85+x)/5=86   x=(5*86)-(4*85)   x= 430 - 340= 
<gadget id="calculator">430 - 340</gadget>
<output>90</output>
90   90orrect answer is 90
<result>C</result>
On a test average (arithmetic mean) test score for 4 students is 85. What must be 5th student's score that average score for 5 students to be 86?