Average Problems( Week 23 Practice) 1. There are 6 math exams during the semester. Kevin has taken 5 exams so far and the scores were 92, 87, 84, 86, and 81. What will Kevin need to score on his final math exam to have an average score of 86 for the semester? 2. There are 3 groups of numbers. The first group has 5 numbers with an average of 4. The second group has 4 numbers with an average of 5 and the third group has 11 numbers with an average of 15. What is the average of all these numbers? 3. The average of 11 numbers is 9. One of numbers was then changed to 4. The average of all the numbers becomes 6 now. What was the number before it was changed? 4. There are 6 numbers. Their average is 10. The average of the first 3 numbers is 6. The average of the last 4 numbers is 16. What is the 3rd 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 12. What is the average of the first 13 numbers in the set? |