=+4.20 The ministry of Health and Long-Term Care in Ontario, Canada publishes information on the time that patients must wait for various medical procedures on its web site (www.health.gov.on.ca). For two cardiac procedures completed in fall of 2005 the following information was provided:

Number 90%

of Com- Median Mean Completed Wait Wait pleted Proce- Time Time Within Procedure dures (days) (days) (days)

Angioplasty 847 14 18 39 Bypass surgery 539 13 19 42