Practical Regression Problem

Lets try to do the regression analysis of the the following dataset Refer Here

Lets check for Linearity
 Mileage vs price
 Engine vs price
 Year vs price
 Mileage vs log(price)
 Engine vs log(price)
 Year vs log(price)

Since we have 7distinct categories in category variable Brand, we have created the six dummy variables (Rule => n1)

Lets create one more variable for log(mileage) just for understanding

Regression Analysis of
 Log price and Log mileage
 Log price and year
 Log price and Engine
 log price and log mileage, year and Engine
 Log price vs log mileage, year, engine and other categorical dummies (brands)
Lets do some more analysis
 For 1% in mileage, the price decreases by 0.11%
 For each unit (litre) increase in Engine volume, log price increase by 0.14
 For each extra unit (litre increase) of volume log increases by 0.14 and price increases by 15%
 When year increases by 1 year the log price increases by 0.04 and price increase by 4%
 Solved sheet Refer Here