This aplication can be used to study the relationship between the speed and the distance reached by a car. The data used was taken from the CARS data set. You can fit the regression lines, show the leats squared lines and see a prediction made by the model for a given speed value and its dist value over the red line. The application also shows the diagnostics plots, where the user can select a number from 1 to 6 and see the respective diagnostic plot he/she wants to explore. The app can be found here.

The characteristics of the fitted model are the following.

Call:
lm(formula = dist ~ speed, data = cars)

Residuals:
    Min      1Q  Median      3Q     Max 
-29.069  -9.525  -2.272   9.215  43.201 

Coefficients:
            Estimate Std. Error t value Pr(>|t|)    
(Intercept) -17.5791     6.7584  -2.601   0.0123 *  
speed         3.9324     0.4155   9.464 1.49e-12 ***
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Residual standard error: 15.38 on 48 degrees of freedom
Multiple R-squared:  0.6511,    Adjusted R-squared:  0.6438 
F-statistic: 89.57 on 1 and 48 DF,  p-value: 1.49e-12

After fitting the model, I plotted it with the data.