Data Analysis: Effect and Prediction of Automatic or Manual Transmission on Miles Per Gallon of cars

Heng Kar
28 Feb 2016

Overview

This analysis is to explore the relationship between a set of variables on miles per gallon (MPG) (outcome). The analysis are particularly focus in the following two questions:

  • “Is an automatic or manual transmission better for MPG”
  • “Quantify the MPG difference between automatic and manual transmissions”

Exploring Data With Plot

From plot, we can see some higher correlations between variables like

  • “hp”
  • “wt”
  • “am”

plot of chunk unnamed-chunk-1

Regression Analysis and Prediction

The regression model will predict MPG based on, Transmission type, Weight and Horsepower.

Linear regression model:

fit <- lm(mpg ~ am + wt + hp, data = mtcars)

Coefficient:

Estimate Std. Error t value Pr(>|t|)
(Intercept) 34.0028751 2.6426593 12.866916 0.0000000
amManual 2.0837101 1.3764202 1.513862 0.1412682
wt -2.8785754 0.9049705 -3.180850 0.0035740
hp -0.0374787 0.0096054 -3.901830 0.0005464

Details of Application

Shiny App Screen Shot Shiny App Shiny App

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