Question

Greg earn $15,$18, $12, $20,and $25 for each of the five lawns he mowed. Greg wants to earn a mean of $20 per lawn. how much must he charge for his next mowing job?

Answer 1

So your answer is $30

Answer 2

To find the mean of a set of data, you add up all of the values and divide that by the amount of values you have. Using this, we can find the answer by reversing this process.

If we want the mean to be $20, then all of the values added together and divided by 6 (because he's going to get one more value) must equal 20. Therefore we can multiply 20 by 6, which is 120, and subtract all of the values we currently know, so:
15 + 18 + 12 + 20 + 25 = 90
120 - 90 = 30

So your answer is $30.

I hope this helps!