Winchard's average (arithmetic mean) test score on 4 tests is 78. What must be the student's score on a 5th test for the Winchard's average score on the 5 tests to be 80?	Choose the correct choice from the following answers:
A) 80
B) 82
C) 84
D) 86
E) 88
E. 88   Winchard must score at least an 80 for sure. If he scores an 8, then he will need to score 2 pots for each of the 4 other tests tomake upthe difference. They each were at 78 (at least the average is, but this is a small point and doesn't matter to the answer). So 4 tests that were each 2 points short of the 80 average that is desired means the next test must be 8 points higher than the desired average, so  80+8= 
<gadget id="calculator"> 80+8</gadget>
<output>88</output>
88.
<result>E</result>
Winchard's average (arithmetic mean) test score on 4 tests is 78. What must be the student's score on a 5th test for the Winchard's average score on the 5 tests to be 80?