clear
sysuse auto
/*
graph bar price, over(rep78)
graph dot price, over(rep78)
*/
collapse (mean) price (semean) seprice = price, by(rep78)
gen uclm = price + 1.96*seprice
gen lclm = price - 1.96*seprice

graph dot (asis) lclm price uclm, over(rep78)

graph twoway (rspike lclm uclm rep78) (scatter price rep78)

* contract catvar, stats

clear
sysuse auto

contract rep78 foreign, freq(freq) percent(pct) zero nomiss