Modeling Real World Data: Scatter Plots

Key Topics

• Bivariate Data: data that contains two variables

• Scatter Plot: a set of bivariate data graphed as ordered pairs in a coordinate plane

Constructing a Scatter Plot

Construct a scatter plot at your desk using the above data

Notice how the gap in the

values is noted on the graph

Key Topics

• Line of fit: a line drawn that closely approximates the data

• Prediction equation: equation of the line of fit used to approximate the data

Key Topics

Finding prediction equation is just finding the equation of the line of fit: pick two points, find the slope, then find the equation for the line

(2,122) and (8,153), m =

Equation for line: y – 122 = (x – 2)6

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6

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Key Topics

• We can now use our prediction equation to estimate the median house prices in future years

Equation for line: y – 122 = (x – 2)6

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For example in the year 2004 we can say the median house value will be approximately $164,000

y – 122 = (14 – 2)6

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