Answer:
100
Explanation:
Let x be the value he needs on the 4th test
To find the average, we add up all the scores and divide by the number of tests
(85+92+95+x) /4
We know the average is 93
(85+92+95+x) /4 = 93
Multiply each side by 4
(85+92+95+x) /4 *4 = 93*4
(85+92+95+x) = 372
Combine like terms
272 +x = 372
Subtract 272 from each side
272+x-272 = 372-272
x = 100