SOLUTION: please answer this question: the average cost of tuition fees, room and board for 2 year institution increased from $1979 in 1980 to $4895 in 1997. A) find the linear function t

Algebra ->  Rational-functions -> SOLUTION: please answer this question: the average cost of tuition fees, room and board for 2 year institution increased from $1979 in 1980 to $4895 in 1997. A) find the linear function t      Log On


   



Question 159071: please answer this question: the average cost of tuition fees, room and board for 2 year institution increased from $1979 in 1980 to $4895 in 1997.
A) find the linear function that will give average expense of a two year institution E, as a function of time, x, where x is defined to be the number of years since 1980.
B) use the equation to predict the average expense associated with 2010.
i tried to find the linear function but i got stuck i been here for hours and i could figure it out. i got E=17x+1979-4895

Answer by vleith(2983) About Me  (Show Source):
You can put this solution on YOUR website!
Let's do this.
We'll setup a linear equation in the form y = mx +b that uses the given info.
y is the cost of tuition
x is the number of years after 1980
You are given : $1979 in 1980 to $4895 in 1997. So you know 2 points on the line. Thise points are {0, 1979) and (17, 4985). We find the x values as x+=+year+-+1980
First let's find the slope of the line
m = (y[2] - y[1])/(x[2] - x(1])
m+=+%284985+-+1979%29%2F%2817+-0%29
m+=+3006%2F17
m+=+176.8
b is the y intercept. That is the point where the x value is 0. So for us b+=+1979
We have what we need. Just plug it all in
y+=+mx+%2B+b
y+=+176.8+%2A+x+%2B+1979
Check the eqaution using the two points you know. At year 1980, x =0, so y = 1979. That is correct
At year 1997, x = 17. So y+=+176.8+%2A+17+%2B+1797 = 4984.6 close enough
So for part A) E+=+176.8+%2A+x+%2B+1979 (same equation, just use the variables the problem states.
Finally, you are asked to estimate the cost in the year 2010.
In 2010 x+=+2010+-+1980 = 30
Plugging that into y+=+176.8+%2A+x+%2B+1979 yeilds
y+=+176.8+%2A+30+%2B+1979
y+=+5304+%2B+1979
y+=+7283