5.7 – Predicting with Linear Models

Today we will be learning how to:◦ Determine whether a linear model is appropriate

◦ Use a linear model to make a real-life prediction

Modeling real-life situations is a major goal for this course

Today we will decide whether a linear model can be used to represent real-life data

Example 1 The manager of a

restaurant made the following table.

Which data are better modeled by a linear model?

Average Price Per Pound ($)

Year Fish Meat

1991 3.75 2.50

1993 4.25 2.70

1995 5.25 3.00

1997 6.75 3.30

1999 8.75 3.50

Example 2 Write a linear

model for the average meat prices given in Example 1.

Average Price Per Pound ($)

Year Fish Meat

1991 3.75 2.50

1993 4.25 2.70

1995 5.25 3.00

1997 6.75 3.30

1999 8.75 3.50

Linear interpolation – method of estimating the coordinates of a point that lies between two given data points

Linear extrapolation – method of estimating the coordinates of a point that lies to the right of left of all of the given data points

Example 3◦ Use the linear model from Example 2 to estimate

the average price per pound of meat in the given year. Tell whether you use linear interpolation or linear extrapolation. 2002

1998

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