can anyone help with with parts b, c, and d please?(:

Question

heyitslizzy13 · Answer

attachment

phi · Answer

part b wants you to find the equation of a line.
Its first point is at x=0  
what is the y value when x is 0?

heyitslizzy13 · Answer

995?

phi · Answer

yes, so the first point is (0,995)
you now want the point at x=8.  you can read it off the graph 
what is it ?

heyitslizzy13 · Answer

(8,1464)

phi · Answer

now we have two poins  (0,995) and (8,1464)
the starting point is the equation
y= m x + b

we need to find m.  m is the slope, and slope is change in y divided by change in x
can you find the slope between these two points?

phi · Answer

change in y is 1464-995 = ?

heyitslizzy13 · Answer

yes okay I got 469/8 for the slope :)

phi · Answer

ok, now use the first point (0,995) 
y = (469/8) x + b
replace y with 995 and x with 0
what do you get ?

heyitslizzy13 · Answer

b=995?

phi · Answer

yes.  (we could have use the other point and we would get the same answer for b... but it would be harder arithmetic)

anyways,
y=  (469/8) x + 995

heyitslizzy13 · Answer

wow, okay thanks :)) can you explain part c to me please?

phi · Answer

the slope of that line is the average "change in sales" per year from 2000 to 2008

phi · Answer

can you do part D?

heyitslizzy13 · Answer

i'm not sure how to

phi · Answer

they want you to find y using your equation
what x value should we use to get 2010 ?
any idea ?

heyitslizzy13 · Answer

10!

heyitslizzy13 · Answer

so just plug it into the equation and get my answer?(:

phi · Answer

yes. I would change the slope to a decimal, multiply by 10 then add 995
then round to the nearest whole number.

heyitslizzy13 · Answer

thanks so much!

phi · Answer

what did you get ?

heyitslizzy13 · Answer

$1581.25 million

phi · Answer

yes.  and because all the other numbers in the graph are whole numbers it makes sense to round to 1581.  (you can make a note that you rounded it, in case your teacher wonders)

I would say it is a reasonable estimate because the graph of the points is roughly a straight line  (the dots are not scattered all over the place)
and we are only estimating 2 years into the future.  (it would be less reasonable to estimate say 20 years into the future)

heyitslizzy13 · Answer

ok, thanks! :)