Math

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Name_________________

Written Homework #1 Sections 1.3 & 2.1

1. The table below lists U.S. fossil fuel consumption as a percentage of a total fuel consumption for selected years.

Year Consumption (%)

1980 87

1985 85

1990 85

1995 82

2000 83

2005 80

a. Find a linear regression model for this data where x represents the number of years since 1980 and y represents the corresponding percentage of fossil fuel consumption.

b. Interpret the slope of the model.

c. Interpret the x & y -intercepts of the model.

d. Use the model to predict fossil fuel consumption in 2020.

e. Use the model to estimate the first year for which fossil fuel consumption is less than 65% of total energy consumption. (Write and solve a linear inequality)

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2. Find the domain of each function algebraically. Write the domain using interval notation.

a. 3 4

( ) 7

x f x

x

 



b. ( ) 7g x x 

c. ( ) 7

x h x

x 

