Question 282709
Start with 1950, which which we are told should be year t=0.
y = 151 million in 1950.
y = mx + b is the slope-intercept form.
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We're using the year to predict the population, so t=x-axis.
The population is plotted on y-axis as the dependent variable.
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So we would define it as:
y = mt + 151, which define defines the point (0,151)
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1990 would be t=40
1990 population is 249 million
So it would be plotted at (40,249)
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The slope = rise/run
rise = change in y = 249-151 = 98
run = change in x = change in t = 40-0 = 40
m = slope
m = 98/40
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That means our equation is:
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y = 98/40*t + 151
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Graph it to check
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{{{graph(500,500,-10,50,-10,300,98/40*x+151)}}}
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