* do-file for Supplementary Exercises 7.102 and 7.103 of IPS7e
version 13 /* works also for version 14 */

import delimited "H:\VHM\VHM801\Datasets\csv\Chapter 7\ex07_102.csv", clear
rename r change
bysort group: stem change 
bysort group: summarize change, detail
bysort group: swilk change
bysort group: ci change
ttest change, by(group) unequal