Question

PLEASE HELP WILL FAN AND MEDAL.
Which equation best represents the regression line for the data given in the table below?

a) y=-3x+3
b) y=3x+3
c) y=3x-3
d) y=-3-3

Answer 1

Going from x = 1 to x =2, f(x) decreases
Going from x = 6 to x =7, f(x) decreases
But everywhere else, f(x) increases with x.
So the slope has to be positive which eliminates choices a and d.

Answer 2

Okay, so how do I find the answer?

Answer 3

I think it's c

Answer 4

Put in x values from x = 2 to x = 6 in b) and c) and see which gives values closer to f(x).

Yes, I am also leaning towards c).

Answer 5

Okay!

Answer 6

Could you help me with another?

Answer 7

Which equation defines the graph of y=x^3 after it is shifted vertically 5 units down and horizontally 4 units left?

a) y=(x-4)^3-5
b) y=(x+5)^3-4
c) y=(x+5)^3+4
d) y=(x+4)^3-5

Answer 8

I think, it's d but I am not sure.

Answer 9

For the previous question, 3x - 3 is the best approximation among the given choices:
http://www.wolframalpha.com/input/?i=linear+regression+%281%2C3%29%2C++%282%2C0%29%2C++%283%2C4%29%2C++%284%2C9%29%2C++%285%2C15%29%2C++%286%2C18%29%2C++%287%2C14%29

Answer 10

Okay, thanks!! Could you help me with the other?

Answer 11

If f(x) is shifted vertically DOWN by 5 units it will become f(x) - 5
If then it is shifted horizontally 4 units LEFT it will become f(x+4) - 5
We are given f(x) = x^3
f(x+4) - 5 = ?

Answer 12

f(x) = x^3
f(x+4) = (x+4)^3
f(x+4) - 5 = (x+4)^3 - 5

Answer 13

I got the left and right confused.

Answer 14

So it's c?

Answer 15

d)

Answer 16

*d*

Answer 17

oh okay, thank you!!

Answer 18

yw.

Answer 19

Would you mind helping me with a few others?

Answer 20

close this one. There are others here that can help too. I have 5 messages that I'd like to answer.

Answer 21

Okay. Thanks anyway

Answer 22

A solution and plot using Mathematica 9 is attached.