00:02
Hi there.
00:03
This question is a question about calculating average.
00:08
So you know what an average? we add together each of the values and divide by the number of the values to get the average.
00:16
So for this problem, it looks something like this.
00:21
We need to take the sum of the four grades, divide that by four because that's how many we are adding together.
00:34
And we want that average to equal 80.
00:40
You know right now is the first three grades average 78.
00:45
And we want to know what we need to get on that fourth test to get up to that 80%.
00:50
So if the first three grades average 78, we could do some creative math to figure out scores that would average up to 78, or we could take the easy way and just assume a score of 78 for each of those.
01:09
Because if we take 78 plus 78 plus 78, divide by three, the average is 78...