Regression lines

To add a regression line (straight line) to your plot which geom should you use?

Which argument of geom_smooth() will add a purple regression line?

Which argument of geom_smooth() will remove the confidence intervals of the regression lines? 

Assume your data is not normally distributed: you have to use a generalized linear model to fit a line. Which argument of geom_smooth() will do that?

With the method.args argument of geom_smooth() you can set the family argument of the glm. Assume that the data follow a poisson distribution after log transformation.

Which line of code will generate the following plot:

How many regression lines will this code generate? (assuming there are 4 groups defined by smoke). Answer should be an integer. 

ggplot(babies,aes(ht,wt,color=smoke)) + geom_point() + geom_smooth(method=”lm”)

How many regression lines will this code generate? (assuming there are 4 groups defined by smoke). Answer should be an integer. 

ggplot(babies,aes(ht,wt)) + geom_point(aes(color=smoke)) + geom_smooth(method=”lm”)

Which package do you need to add the equation to the plot? 

Which function to do linear regression on data that do not follow a normal distribution?

How to fit a linear model to right-skewed positive data?