Average Problems( Week 23 Practice) 1. There are 6 math exams during the semester. Ben has taken 5 exams so far and the scores were 91, 83, 80, 97, and 83. What will Ben need to score on his final math exam to have an average score of 89 for the semester? 2. There are 3 groups of numbers. The first group has 4 numbers with an average of 9. The second group has 5 numbers with an average of 8 and the third group has 11 numbers with an average of 14. What is the average of all these numbers? 3. The average of 11 numbers is 13. One of numbers was then changed to 4. The average of all the numbers becomes 12 now. What was the number before it was changed? 4. There are 9 numbers. Their average is 16. The average of the first 6 numbers is 12. The average of the last 4 numbers is 23. What is the 6th number? 5. Consecutive numbers are natural numbers that follow in order, such as 1,2, 3, 4, 5,..., and so forth. Suppose the average of 21 consecutive numbers is 19. What is the average of the first 15 numbers in the set? |