To have an average of 92 with four tests, you have to multiply 92 by 4 to find the total score.
[tex] 92 \times 4 = 368 [/tex]
The total score must be 368. Three of the scores are given. Add the three scores and subtract that from 368.
[tex] 94+96+88 = 278 [/tex]
The total of the three scores is 278. The total must be 368. Subtract 278 from 268 to find the missing score.
[tex] 368 - 278 = 90 [/tex]
The student must have a score of 90 to have an average score of 92.