Question

Find a quadratic model for the annual amount in millions of dollars spent on water gardening based on number of years since 1999. Then, estimate the amount that people in the United States will spend on water gardening in 2015.

Answer 1

This problem is identical to those two we did before; the only addition to it is that after you've obtained the quadratic, you substitute a value of x representing the year 2015.

Answer 2

Yes, so I need to find the quadratic! Okay let me work on it real quick

Answer 3

Hold a mom.

Answer 4

You could use those year figures 2000, 2008, etc.,
or you could represent 2000 by 0 and 2015 by 15, and thus work with smaller numbers

Answer 5

either way would be OK, but I'd definitely take the latter.

Answer 6

I think I would rather use the smaller numbers. So how would I start that off?

Answer 7

where your table has x=2000, substitute z=0; where x=2003, use z=3, and so on.
You'd come up with a quadratic in y (dependent variable) and z (indept. var.)

Answer 8

So for the point (2000, 943) I would just use

a(0)^2 + b(0) + c = 943 ?

Answer 9

that's right! and when you have the quadratic you wanted, merely substitute z=15 to obtain a prediction for the year 2015.

Answer 10

Do I still have to use three of the points to find the quadratic?

Answer 11

yes, but you may use any of the 3 that you care to or happen to pick.

Answer 12

Bet this is becoming much easier for y ou than it was.
Suggest, however, that y ou decide for yourself whether focusing on this problem (which from now on is hardly any different from the previous two), or focusing on a new topic, would most benefit you.

Answer 13

Yeah, let me go find something else real quick!

Answer 14

Smart move on your part.

Answer 15

Pls treat it as a new question to post.