• This app allows you to see how much Americans spent on 5 different categories of household expenditures between 194 and 1960. You can select the category and view a graph, showing the trend line in the 20 year period, measured in billions of dollars.
• Based on the rate of growth in the 20 year period, we can predict what growth would have been in the subsequent years. The dropdown lets you select a different year, and find the linear prediction of expenditures in the selected year for the category you chose.

Example: - Here is the raw Data for the expenditure category "Food and Tobacco".

##                  X1   X2 value
## 1  Food and Tobacco 1940  22.2
## 6  Food and Tobacco 1945  44.5
## 11 Food and Tobacco 1950  59.6
## 16 Food and Tobacco 1955  73.2
## 21 Food and Tobacco 1960  86.8

• Assume you selected "Food and Tobacco" as the category and 1965 as the year to predict for.

• You can see the graph contains an X-value for 1965 and the Y-value is a linear prediction.