00:01
So we want to find the quadratic model that fits this model best.
00:04
And so what i've done is going to put the data into my calculator, and i made sure i use the numbers 5, 10, 15, 20, and 22 for my x values because they want x to be the years since 1990.
00:21
That means t equals 0 is going to equal 1990.
00:25
So 1995, we mean t equals to 5.
00:28
Be careful with that last one.
00:31
2012 is going to eb 22.
00:34
So they try to say that you're going to all in increments of five, but not for that last value.
00:40
So when i got the quadratic model, i get y equals a x squared plus bx plus c, and i'm going to get y equals negative 2 .7x plus 72x.
00:53
That should be a squared plus 548.
00:58
And there's a pretty good correlation here of .97, so i'm happy with that.
01:02
So they want us to use the highest point of this, which is going to be at the vertex.
01:08
So i'm going to go ahead and find my vertex.
01:10
X portion of my vertex is negative b over 2a.
01:14
So i'm going to say that's going to be negative...