00:01
Problem, what we want to do first is write an inequality to represent the given situation.
00:05
So what we were told is that melinda's first two test grades in psychology were an 87 and 94, as i noted above.
00:12
We want to figure out what she would need to get on her third test to have an average of at least 90.
00:18
So in all, she's going to have three tests, but we don't know what she got on the last test.
00:23
And when we don't know something in math, we call it x.
00:25
So what i'm looking at is her three scores would be an 87, a 94, and x.
00:31
Well, remember, to find the average of numbers, you add up the number of test scores, and you're going to divide by how many tests she took.
00:39
So in this case, we're going to have to add 87 plus 94 plus x, and we have to divide that all by three because she took three tests.
00:49
Now, she wants her average to be at least a 90, meaning she wants this value to be anything bigger or equal to 90, because that's what at least means...