pdf("airq4.pdf")

airq4 <- read.fwf("C:\\data\\airq4.txt", width=c(3,6,11,10,6,8,10,8,10),
 col.names=c("city1","city2","pop1","pop2","dist","fare00",'pass00","fare01","pass01"))

attach(airq4)

names(airq4)

rev00 <- 13*fare00*pass00

rev01 <- 13*fare01*pass01

pctchng <- 100*(rev01-rev00)/rev00





dev.off()