Lab 12 results

1. Cars and trucks

The number of cars and trucks increases by about 3.5 million vehicles per year, on average.

1.b. Equation forecast using slope and intercept function estimates

Slope = 3.485596; Intercept = -6757.9

Y = 3.485597 * 2020 -6757.9

Y = 283.00

The forecast is that there will be 283 million cars and trucks in the U.S. in 2020

1.c. Trendline extension method

1.d. Discuss confidence in forecast

1.e. Predict with there were zero vehicles

0 = 3.485597 * X -6757.9

1.e. Predict with there were zero vehicles

0 = 3.485597 * X -6757.9

6757.9 = 3.485597 * X

1.e. Predict with there were zero vehicles

0 = 3.485597 * X -6757.9

6757.9 = 3.485597 * X

6757.9/ 3.485597 = X

1.e. Predict with there were zero vehicles

0 = 3.485597 * X -6757.9

6757.9 = 3.485597 * X

6757.9/ 3.485597 = X

1938.8

1.e. Trendline extension method

1.f. Add historical information

Ransom E. Olds began mass producing in 1902; Henry Ford started in 1914.

The model predicted miserably.

Apparently something fundamental changed between the early 1900s and 1970 to make automobile purchase easier.

1.g. Forecast when 300 million vehicles

300 = 3.485597 * X -6757.9

300 = 3.485597 * X -6757.9

7057.9 = 3.485597 * X

300 = 3.485597 * X -6757.9

7057.9 = 3.485597 * X

7057.9/ 3.485597 = X

300 = 3.485597 * X -6757.9

7057.9 = 3.485597 * X

7057.9/ 3.485597 = X

2024.8

1.h. Forecast number of cars and trucks in 2050

Y = 3.485597 * 2050 -6757.9

Y =387.57

The forecast is that there will be over 388 million cars and trucks in the U.S. in 2050

2.b 2010 coal consumption, equation method

Slope = .299633; intercept = -577.68

Y = .299633 * 2010 -577.68

Y = 24.582

2.b 2010 coal consumption, trendline extension method

2.c. Prediction when consumption equals 30 quads

30 = 0.299633 * X -577.68

2.c. Prediction when consumption equals 30 quads

30 = 0.299633 * X -577.68

607.68 = .299633 * X

2.c. Prediction when consumption equals 30 quads

30 = 0.299633 * X -577.68

607.68 = .328625 * X

607.68/ .299633 = X

2028 = X

2.e. Discussion of changes affecting validity of prediction