line of best fit

Since "X" is the number of years since 1980, I would convert the years and subtract each of them by 1980. For example, in 1985, the cost was $1.06. Therefore, I would use the number "5" since that is how many years it has been since 1980. This applies to all of the years listed.

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In order to find the equation of the line (based off the data), you would have to use the equation model:

$$y=mx+b$$

The variable "m" represents the slope of the line, while "b" represents the y-intercept.

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The first step is to find the slope (m) by using this formula:

slope = △X/△Y

This is how you solve for the slope:

slope = △Y/△X → (y2-y1)/(x2-x1)

After substituting all of the values, you would get this for your slope:

$$y=1/25x+b$$

According to this "almost-complete" equation, the slope is equal to 1/25.

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Now, "b" is equal to the y-intercept of the graph.

To find the "b" variable, I would look at the table above. The first point listed is (0,1). Therefore, you know that the origin of the graph is at 0. As a result, The y-intercept is equal to 1.

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FINALLLYYY! You have the information you need to answer your question! LOL

The model of the equation is the following:

$$y=mx+b$$

m = 1/25

b=1

soooooooo........

The equation is y = 1/25x + 1

WOW BJ that is impressive 

Thank you, Melody! :)