test_money.R

money=c("$50000","$50,000","50,000",50000,"50000",NA)
mean(money)

## Warning in mean.default(money): argument is not numeric or logical:
## returning NA

## [1] NA

money=gsub(",","",money)
money

## [1] "$50000" "$50000" "50000"  "50000"  "50000"  NA

money=gsub("\\$","",money)
money

## [1] "50000" "50000" "50000" "50000" "50000" NA

money=as.numeric(money)
money

## [1] 50000 50000 50000 50000 50000    NA

mean(money)

## [1] NA

mean(money,na.rm=T)

## [1] 50000

money=na.omit(money)
money

## [1] 50000 50000 50000 50000 50000
## attr(,"na.action")
## [1] 6
## attr(,"class")
## [1] "omit"

mean(money)

## [1] 50000