Average Problems( Week 23 Practice) 1. There are 6 math exams during the semester. Ed has taken 5 exams so far and the scores were 81, 96, 87, 99, and 98. What will Ed need to score on his final math exam to have an average score of 91 for the semester? 2. There are 3 groups of numbers. The first group has 3 numbers with an average of 8. The second group has 4 numbers with an average of 9 and the third group has 3 numbers with an average of 13. What is the average of all these numbers? 3. The average of 43 numbers is 11. One of numbers was then changed to 6. The average of all the numbers becomes 8 now. What was the number before it was changed? 4. There are 6 numbers. Their average is 20. The average of the first 2 numbers is 19. The average of the last 5 numbers is 21. What is the 2nd 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 19 consecutive numbers is 20. What is the average of the first 7 numbers in the set? |