* do-file for Supplementary Exercise 8.62 of IPS7e
version 18 /* works also with versions 13-17 */

* 90% CI and test based on normal approximation
prtesti 78 63 77 43, count level(90)
* 90% plus four CI (but test is not valid)
prtesti 80 64 79 44, count level(90)