READ THIS FIRST!!! This story, like all of the other stories written by us, is a fictional parody, we write these fictitious stories for fun and because we can. The Supreme Court of the United States has ruled that parodies involving famous people are perfectly and totally legal under the United States Constitution (ruling occurred as a result of the case “Hustler Magazine, Inc et al vs. Jerry Falwell” in 1988).
bid_ask_df[, c(3, 4)] %>% mutate(mid = .[] + .[]) %>% select(-1, -2) %>% summarise_each(funs(mean, sd))