Question 687686
To solve, we first need to know how to find the average of a group of numbers. To find the average of a group of numbers, you add all the numbers together and divide that answer by the number of numbers you have. For instance, to find the average of 1, 2, 3, 4 and 5, we would add all the numbers together, which would equal 15. We would then divide that number by 5, because there are 5 numbers total: 15/5 = 3. So the average is 3. 


Now, to find the average in your problem, we need to look at what we know: 


He received an 85 and 60 on two of the test scores


He needs an overall average of 70


Let's set this up in equation form:


{{{(85 + 60 + x)/3 >= 70}}}


Now, let's get rid of our fraction on the left.  We can do this by multiplying the entire equation by 3, giving us:


85 + 60 + x >= 210


Next, combine the numbers on the left, which will give us:


145 + x >= 210


Finally, subtract 145 from both sides, which will give us our answer:


145 + x - 145 >= 210 - 145 = 


x >= 65


So, in order to average at least 70, he must score a 65 or higher on his third test.