Answer:
Minimum 57
Step-by-step explanation:
Average, or, Mean has the formula:
Average = Sum of all numbers/Number of numbers
If, Tao wants 85 as average in 5 exams, his sum of 5 exams needs to be:
Average = Sum of all numbers/Number of numbers
85 = Sum/5
Sum = 5 * 85 = 425
Since, the average of 4 tests is already 92, the sum of 4 tests is:
92 = Sum/4
Sum = 4 * 92 = 368
So, he needs atleast (425 - 368) = 57 on his first test to make total average for 5tests to be 85.
So, minimum 57 needs to be scored