There are eight numbers, and their average is 7.5. It is known that the average of the first five numbers is 8.8, and the average of the last four numbers is 9.5. What is the fifth number?

There are eight numbers, and their average is 7.5. It is known that the average of the first five numbers is 8.8, and the average of the last four numbers is 9.5. What is the fifth number?

(8.8*5+9.5*4)-(7.5*8)=24