Al must score 96 in his final test to get an average of 81.
An average or mean is one number chosen to represent a group of numbers; it is often the sum of the numbers divided by the number of numbers in the group.
If every number in a list is the same number, then the average of the numbers in the list is also this number. Every one of the diverse varieties of average shares this characteristic.
The sum of the of the numbers 2, 3, 4, 7, and 9 is 25, the average of the numbers is equal to 25 divided by 5=5.
Let Al scores x on final test.
Average score on first 3 tests=76
Total score on first 3 tests=76×3=228
Total score in 4 tests=228+x
Average score of 4 tests=(228+x)÷4
Average to be obtained in 4 tests=81
therefore we can equate the two expressions to calculate x.
(228+x)÷4=81
or, 228+x=324
or,x=324-228
or, x=96
Hence Al needs to get 96 on his final test so that his average is 81.
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