Ti 89
Enter the data
APPS 6 (the data/matrix editor) 3 (New)
Name it cubic
In C1 enter 10, 11, 12, 13, 14, 15
move over and up 
In C2 enter 90, 99, 100, 102, 107, 128
while still in the data editor
F5 (this is called the calculate window
make the type CubicReg > 3
make x c1
make y c2
store regEQ to y1(x)
enter

a dialog with the answers
 y = a x^3 + b x^2 + c x + d
   a = 1.166667
   b = -42.392857
   c = 513.22619
   d = -1969.714286
   ...

appears this is the best cubic fit.
enter 

green diamond F1 (y= key)
will show the equatin in the y1(x)=
go up and highlight plot1 ^ enter
	plot type scatter
	make x c1
	make y c2

green diamond F2 (window key)
xmin = 10
xmax = 15
ymin = 90
ymax = 130

green diamond F3 (graph)

You should see the data and cubic fit in the graph window
Nice fit isn't it.

Another check is to repeat this for #23 section 3.3
the answers match the ones in the back of the text
with slight differences in the least significant decimal places.