Question

The course grade in a statistics class is the average of the scores on five examinations. Suppose that a student's scores on the first four examinations (out of 100) are 66, 78, 94, and 83. What is the highest course average possible after the last examination? A) 6 B) 100 C) 84 D) 80

Answer 1

84 is the highest possible course average

Explanation:

Total number of examinations = 5

Average = sum of scores in each examination/total number of examinations

Let the score for the last examination be x.

Average = (66+78+94+83+x)/5 = y

5y = 321+x

x = 5y -321

If y = 6, x = 5×6 -321 =-291.the student cannot score -291

If y = 80, x = 5×80 -321 =79.he can still score higher

If If y = 84, x = 5×84 -321 =99.This would be the highest possible course average after the last examination.

If y= 100

The average cannot be 100 as student cannot score 179(maximum score is 100)