1. Use a linear model to make a prediction.
Make a scatter plot to represent the data. Draw a trend line and write an equation for the trend line. Use the equation to predict the time needed to travel 32 miles on a bicycle.
Speed on a Bicycle Trip
Step 1  Draw a scatter plot. Use a      
straight edge to draw a
trend line. Estimate two
points on the line.
Miles
Time
(min) 5 27 10 46 14 71 18 78 22
107
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2. Use a linear model to make a prediction.
(continued)
Step 2  Stack, Subtract and divide to find the slope.
(22, 127) – (5,27) = 17 , 100 = so let m = 5
100 17
y = m x + b   Use slope intercept form and solve for b.
27 = 5(5) + b Substitute 5 for m and (5, 27) for (x, y).
27 = 25 + b Solve for b
2 = b
Step 3  Predict the time needed to travel 32 miles.
y = 5(32) + 2 Substitute 32 for x.
y = Multiply.
y = Add.
The time needed to travel 32 miles is about 162 minutes.
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