# Regression and Forecasting : Using Data Regression to Predict Sales

YEAR GNP ln(gnp)

1975 1060 6.966024187

1976 1170 7.064759028

1977 1305 7.17395832

1978 1455 7.28276118

1979 1630 7.396335294

1980 1800 7.495541944

1981 2000 7.60090246

1982 2220 7.705262475

1983 2450 7.803843304

1984 2730 7.912056888

The US BNP during the years 1975-1984 is given in the above table.

a. Plot x = years after 1974 against GNP, and use the plot to describe how to fit a curve that could be used

to predict GNP during future years.

b. When the regression on transformed data is done, we find the B=6.86 and B1=0.105. What is the

prediction for 1985 GNP?

Please see the attached file for the fully formatted problems.

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#### Solution Preview

Please see the attached file.

The regression table can be found on the sheet"regresssion table"

YEAR GNP ln(gnp)

1975 1060 6.966024

1976 1170 7.064759

1977 1305 7.173958

1978 1455 7.282761

1979 1630 7.396335

1980 1800 7.495542

1981 2000 7.600902

1982 2220 7.705262

1983 2450 7.803843

1984 2730 7.912057

The US BNP during the years 1975-1984 is given in the above table.

a. Plot x = years after 1974 against GNP, and use the plot to describe how to fit a curve that could be used

to ...

#### Solution Summary

Data regression is used to predict sales. The solution is detailed and well presented.