Question

The table lists data regarding the average salaries of several professional athletes in the years 1991 and 2001. A)use the date points to find a linear function that fits the date. use the function to predict the average salary in 2005 and 2010.
Year….Av erage Salary.
1991 $264,000
2001 $1,450,000
A linear function that fits the date is s(x)=___. (Let x=the number of years since 1990, and let s= the average salary years from 1990).
The predicted average salary for 2005 is $___ (round to the nearest whole number)
The predicted average salary for 2010 is $___(round to the nearest whole number).

Answer 1

did you manage to do something yourself?

Answer 2

yes, i got the first part, but then got stuck at figuring the salary for 2005 and 2010.

Answer 3

what function you got for first part?

Answer 4

i got answer to 2005, but i don't know if its right

Answer 5

s(x)=264,000+118600

Answer 6

you missing an x

Answer 7

(10)

Answer 8

correct?

Answer 9

you missing x in your function

Answer 10

is it suppose to be in front the 264,000? I am not sure

Answer 11

it's not correct either way

Answer 12

s(10)=264,000+118600

Answer 13

i just realised that i was incorrect in previous question ><

Answer 14

uh oh...what happened?

Answer 15

let's go back to it first :D

Answer 16

how did you get that answer for first par? (now i am pretty sure it's really incorrect :P)

Answer 17

hang on a sec..need to find those notes too.

Answer 18

so regarding what i posted previously, my answer for the first part I came up with is y=144,000

Answer 19

then I need to figure how to get the average salary for 2005 and 2010. Thats where I am lost

Answer 20

no it's not 144000

Answer 21

awe..ok.

Answer 22

firstly you ALWAYS need to have x

Answer 23

if there's no x it's always equal to that number, it never changes

Answer 24

ok

Answer 25

so how did you get that? you were doing ok in previous question, so you should do this one too :P

Answer 26

m=264,000-1,450,000/1991-2001=1,186,000/10
1,186,000/10=118,600
y=264,000+1,180,000
y=144,000

Answer 27

you found the correct slope. now use it and one of the points to find the equation
y-y1= m(x-x1)

Answer 28

again you didn't write x :D

Answer 29

and you should use x (year -1990) instead of year

Answer 30

near slope you ALWAYS have x

Answer 31

and also 264,000 is incorrect

Answer 32

phi can you explain how to get that

Answer 33

ok now i don't understand why 264,00 is wrong and not sure where the X should be

Answer 34

x should be near slope

Answer 35

m=264,000-1,450,000/1991-2001=1,186,000/10
this is slope

Answer 36

ok, so i got that part right

Answer 37

no, 264000 is incorrect

Answer 38

If you have time, watch
http://www.khanacademy.org/video/equation-of-a-line-3?playlist=Developmental+Math+2

Answer 39

ok, I;ll go watch it...

Answer 40

\[s(x)=mx+b\]
\[s(x)=118600x+b\]
we have 1991 years and 264000$ but we start as 1990=0, so 1991 is 1
so we have point (1,264000) (x,y) and we put it into function
\[264000=118600\cdot1+b\]
and
\[s(x)=145400\]
so first part answer is
\[s(x)=118600x+145400\]
do you understand?

Answer 41

yes, i get the idea...so how would i figure for 2005?

Answer 42

since years start from 1990, you need 2005-1990=15
so x is 15
and put x inside that function

Answer 43

1991-2005 and 145400-264.000?

Answer 44

oh ok..

Answer 45

so what you got?

Answer 46

2,181,000?

Answer 47

show us how you got that

Answer 48

yeah show us :P

Answer 49

145000/15

Answer 50

no

Answer 51

sorry 145400/15

Answer 52

if you type 145000/15 in the google search window you get 9 666.66667

Answer 53

put 15 instead of x
s(x)=...
s(15)=...

Answer 54

ok, don't confuse me with that phi, :), i am confused enough to figure this stuff out

Answer 55

i did....

Answer 56

phi is right :P

Answer 57

so write down how you did

Answer 58

i know...sorry

Answer 59

s(x)=118600x+145400
s(15)=118600*15+145400

Answer 60

you haven't done this

Answer 61

i kinda had it except for i didn't use the 118600

Answer 62

why you didn't use that? it's function and you need to use everything :D

Answer 63

well, i was getting confused and looking at my previous notes.

Answer 64

so what about year of 2010?

Answer 65

can you do it yourself?

Answer 66

did you get s(15)? Ready to try 2010?

Answer 67

ok, so let me figure for 2010 and ill let you guys know what i come up with OK..

Answer 68

s(20)=118600*20+145400=2,517,400

Answer 69

yay it's correct

Answer 70

:) oh gosh...

Answer 71

thanks you two for all the help, i feel a little stupid haha...but i gotta learn somehow..and sorry phi for being rude...i was really getting frustrated and ready to give up...

Answer 72

khan has a bunch of videos about lines. Search for equation of line. They are all pretty short.

Answer 73

you can watch all video of khan because they are all good :P

Answer 74

thanks, will do...

Answer 75

cool, :) will check that out and save it to my favorites

Answer 76

you can also do some exercises here aswell

Answer 77

nice..gonna need to do LOTs of exercises. other wise, I am back on here.

Answer 78

have a great night you two, thanks again!

Answer 79

u2 ;)