Mean or Average
CONCEPTS
Mean
• Mean is the average of all numbers or (SUM of numbers / COUNT of numbers)
What’s the average of 5, 2, & 3 => (5 + 2 + 3) / 3 = 10/3
• Overall Average: SUM of factors in numerator / SUM of factors in denominator
What’s the average cost / unit if the total cost is $10 and there are 5 units => $10 / 5 units = $2/unit
PRACTICE PROBLEMS
Question 1 What's the mean or average of 4, 9, 8, 3?
-- Answer -- 6
Average = (4 + 9 + 8 + 3) / 4 = 24/4 = 6
Question 2 If there are 345 points scored on 5 tests, what’s the average score?
-- Answer -- 69 points / test
Average = 345 points / 5 tests = 69 points / test
Question 3 Jon ran 5 mi in 30 min, then 3 mi in 20 min. What's the average speed for both segments?
-- Answer -- 4/25
Average speed = (sum miles) / (sum minutes) = (5 + 3) / (30 + 20) = 8/50 = 4/25
ACT PRACTICE PROBLEMS
