SOLUTION: Hi, This is my second question regarding word problems. I need to write an equation in either the slope-intercept form, or the standard(general)form. I 1990, there were 4.24

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Hi, This is my second question regarding word problems. I need to write an equation in either the slope-intercept form, or the standard(general)form. I 1990, there were 4.24       Log On


   



Question 155853: Hi, This is my second question regarding word problems.
I need to write an equation in either the slope-intercept form, or the standard(general)form.
I 1990, there were 4.24 million children in the united states with physical disabilities. In 1998 the number was 5.2 million.
a) Assuming that the trend is linear, write an equation relating the two, where y=number of children with physical disabilities in the u.s., and x= the number of years since 1990 (x= 0 corresponds to 1990). I think the slope for should be y=mx+b for the first part but I'm confused about how to use the numbers.
b) Use your equation to answer the following questions:
If this trend continues, how many children with physical disabilities would there be in the u.s in 2010?
Thanks,

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
I need to write an equation in either the slope-intercept form, or the standard(general)form.
I 1990, there were 4.24 million children in the united states with physical disabilities. In 1998 the number was 5.2 million.
a) Assuming that the trend is linear, write an equation relating the two, where y=number of children with physical disabilities in the u.s., and x= the number of years since 1990 (x= 0 corresponds to 1990). I think the slope for should be y=mx+b for the first part but I'm confused about how to use the numbers.
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You have two points: (0,4.24) and (8,5.2)
slope = (5.2-4.2)/(8-0) = 1/8
intercept: if x = 0, y = 4.2
EQUATION:
n(x) = (1/8)x + 4.2
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b) Use your equation to answer the following questions:
If this trend continues, how many children with physical disabilities would there be in the u.s in 2010?
In 2010, x = 10
f(10) = (1/8)*10 + 4.2 = 5.45 million
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Cheers,
Stan H.