1. ## Quartic Regression

2 16.4
3 15.7
4 15.3
5 15.2
6 15.21
7 15.4
8 15.8
9 16.3
10 16.8
11 17.5
12 18.18
13 18.7
14 19.36
15 19.88
16 20.4
17 20.85
18 21.22
19 21.6
20 21.65

I was told find the line of best fit for the above data chart, now I know it is a Quartic function ax^4+bx^3+cx^2+dx+e, and I know how to get the variables a,b,c,d, and e on my calculator but I have no idea how to algerbraically could Thanks.

2. Can you get your calculator to find the inverse of a 5x5 matrix? That's the hardest part. You need five normal equations. Here's the first two...

$e\cdot 19 + d\cdot\sum x + c\cdot\sum x^{2} + b\cdot\sum x^{3} + a\cdot\sum x^{4} = \sum y$

$e\cdot \sum x + d\cdot\sum x^{2} + c\cdot\sum x^{3} + b\cdot\sum x^{4} + a\cdot\sum x^{5} = \sum yx$

Let's see what you get.

3. No, I don't know how to get the inverse of a 5x5 matrix and do you think you could explain how this equation gets the variables, sorry it looks a bit foreign to me.