Question

for the following set of data find an appropriate regression equation (linear, exponential, or logarithmic) state your reason x: 1,2,3,4,5 y: 112,114, 119, 122, 129

Answer 1

ok so look at the y values

you go from +2, +5, +3, +7, etc...what type of pattern do you think it is?

Answer 2

i mean you go from 112 to 114 by adding 2 etc

Answer 3

im not sure i dont know how to do this problem

Answer 4

ok well i would define it as a piecewise function

actually hold on.........hmmmm let me think about this

Answer 5

were looking for a regression equation such as exponential linear or logarithmic

Answer 6

yeah i know...i was just seeing if you could possibly use two different ones and define them only for when x is odd and another for when x is even...

Answer 7

yeah i thought it was exponential and linear but i'm not sure..

Answer 8

its definitely not log

Answer 9

did you plug it in your calculator?

Answer 10

yeah buts its not regression

Answer 11

why not ?

Answer 12

idk..its not perfect linear...

Answer 13

so now what

Answer 14

?

Answer 15

i would just say linear because there is no way to fit it to log or exp

Answer 16

how do you put this in the calculator i don't know how to

Answer 17

what calculator do you have?

Answer 18

ti-83

Answer 19

ok so turn it on
go to stat
go to edit
you'll see like L1, L2, etc
in L1 put in your x values and in L2 put the y values
then quit
do 2nd, Y=
go to 1:
go On

then go zoom, go zoomfit

Answer 20

make sure in Y= that the plot1 is highlighted

Answer 21

ok now what

Answer 22

just go graph

Answer 23

its just points plotted..

Answer 24

haha i know now you can fit the graph

Answer 25

how?

Answer 26

ok so you want to go stat
go to calc
go to linreg(ax+b)
then put L1, L2 after in the main screen

Answer 27

what do u mean main screen

Answer 28

the main screen is where you do all the math...like would do cos(30), 5+1, sqrt(9)...

Answer 29

when you click lin reg(ax+b) it will take you to the main screen

Answer 30

well after i hit lin reg then what

Answer 31

press 2nd 1 , 2nd 2 enter

you get a linear regression y = 4.2x + 106.6

Answer 32

no i got 4x+ 107.4

Answer 33

did you enter it right? hmm........

press 2nd 0
scroll to

actually no...that should not be correct

Answer 34

its close enough :)

Answer 35

okk what do i do now..

Answer 36

justify its linear...haha what stat is this for?

Answer 37

noo but shouldnt there be a line going through those points ?

Answer 38

yeah but look at the graph...

do you know the concept of a floor? its like the greatest integer function...and then add like one to it...that should make it approximate. idk unless it has to be regression....then you could try exponential shifted way up...but its the 4th term that makes me question that possibility...

Answer 39

do i plug the linear regression into y=?

Answer 40

yeah the equation is supposed to be an approximate for the data

Answer 41

but both the linear regression and exponential equations lie in the same place?

Answer 42

...what?

Answer 43

when i plug the linear regression equation into the y= i end up with a line going across the graph and then when i plug in the exponential regression into the y= the line lays in the same place as the linear regression equation line

Answer 44

is your data correct?

idk but i gotta go so when is this due? monday? i can try to help you tomorrow or something...

Answer 45

yea i put 113 instead of 112

Answer 46

107.1678132(1.035666278^x) is tht the expreg?