QUESTION 6 You can use the command "abline(h=c(50))" to create a horizontal line on an existing plot with a y-intercept at 50. True False QUESTION 7 Which R function will save your plot as a pdf file? O plot.save(type = "pdf") O pdf_ploto) O save plot(type = "pdf") Opdf) QUESTION 8 Setting the "cex" parameter to 1.5 (cex = 1.5) indicates symbols will be 150% greater that the nominal size. True False