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Message: % is not cumulative...
Changed By: Burg Boxster
Change Date: August 18, 2011 09:08AM
% is not cumulative...
Change Date: August 18, 2011 09:08AM
% is not cumulative...
% is not cumulative unless 2% of every 1999 sampled (assuming same samples too) failed each year over a 10 year survey. Then you could say over 10 years, 20% of 1999s sampled failed.
Whereas, if over a 10 year review of each MY, you had 2% failure rate per MY (not 2% per MY per survey year and assuming same samples and sample sizes are used for each MY) you'd only have a 2% total failure rate.
Not to be confused w/ a 10 year review of all MYs over the last 10 years... then, in order to have a 20% failure rate you'd need to have the following (assume samples and sample sizes are same for each MY):
MY 2010 - 20% of all 2010s fail in 2010
MY 2009 - 10% failure of all 2009s fail in each year: 2009, 2010
MY 2008 - 6.66% failure of all 2008s fail in each year: 2008, 2009, 2010
MY 2007 - 5% failure of all 2007s fail in each year: 2007, 2008, 2009, 2010
MY 2006 - 4% failure of all 2006s fail in each year: 2006, 2007, 2008, 2009, 2010
MY 2005 - 3.33% failure of all 2005s fail in each year: 2005, 2006, 2007, 2008, 2009, 2010
MY 2004 - 2.85% failure of all 2004s fail in each year: 2004, 2005, 2006, 2007, 2008, 2009, 2010
MY 2003 - 2.5% failure of all 2003s fail in each year: 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
MY 2002 - 2.22% failure of all 2002s fail in each year: 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
MY 2001 - 2% failure of all 2001s fail in each year: 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
Clearer?
Remember the old saying: "Statistics don't lie... but liars use statistics" ;)
More nuances of course but generally speaking this covers the bases. Warm & fuzzier now? :)
Whereas, if over a 10 year review of each MY, you had 2% failure rate per MY (not 2% per MY per survey year and assuming same samples and sample sizes are used for each MY) you'd only have a 2% total failure rate.
Not to be confused w/ a 10 year review of all MYs over the last 10 years... then, in order to have a 20% failure rate you'd need to have the following (assume samples and sample sizes are same for each MY):
MY 2010 - 20% of all 2010s fail in 2010
MY 2009 - 10% failure of all 2009s fail in each year: 2009, 2010
MY 2008 - 6.66% failure of all 2008s fail in each year: 2008, 2009, 2010
MY 2007 - 5% failure of all 2007s fail in each year: 2007, 2008, 2009, 2010
MY 2006 - 4% failure of all 2006s fail in each year: 2006, 2007, 2008, 2009, 2010
MY 2005 - 3.33% failure of all 2005s fail in each year: 2005, 2006, 2007, 2008, 2009, 2010
MY 2004 - 2.85% failure of all 2004s fail in each year: 2004, 2005, 2006, 2007, 2008, 2009, 2010
MY 2003 - 2.5% failure of all 2003s fail in each year: 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
MY 2002 - 2.22% failure of all 2002s fail in each year: 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
MY 2001 - 2% failure of all 2001s fail in each year: 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
Clearer?
Remember the old saying: "Statistics don't lie... but liars use statistics" ;)
More nuances of course but generally speaking this covers the bases. Warm & fuzzier now? :)
Original Message
Author: Burg BoxsterDate: August 18, 2011 09:08AM
% is not cumulative...
% is not cumulative unless 2% of every 1999 sampled (assuming same samples too) failed each year over a 10 year survey. Then you could say over 10 years, 20% of 1999s sampled failed.
Whereas, if over a 10 year review of each MY, you had 2% failure rate per MY (not 2% per MY per survey year and assuming same samples and sample sizes are used for each MY) you'd only have a 2% total failure rate.
Not to be confused w/ a 10 year review of all MYs over the last 10 years... then, in order to have a 20% failure rate you'd need to have the following (assume samples and sample sizes are same for each MY):
MY 2010 - 20% of all 2010s fail in 2010
MY 2009 - 10% failure of all 2009s fail in each year: 2009, 2010
MY 2008 - 6.66% failure of all 2008s fail in each year: 2008, 2009, 2010
MY 2007 - 5% failure of all 2007s fail in each year: 2007, 2008, 2009, 2010
MY 2006 - 4% failure of all 2006s fail in each year: 2006, 2007, 2008, 2009, 2010
MY 2005 - 3.33% failure of all 2005s fail in each year: 2005, 2006, 2007, 2008, 2009, 2010
MY 2004 - 2.85% failure of all 2004s fail in each year: 2004, 2005, 2006, 2007, 2008, 2009, 2010
MY 2003 - 2.5% failure of all 2003s fail in each year: 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
MY 2002 - 2.22% failure of all 2002s fail in each year: 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
MY 2001 - 2% failure of all 2001s fail in each year: 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
Clearer?
Remember the old saying: "Statistics don't lie... but liars use statistics" ;)
Warm & fuzzier now? :)
Whereas, if over a 10 year review of each MY, you had 2% failure rate per MY (not 2% per MY per survey year and assuming same samples and sample sizes are used for each MY) you'd only have a 2% total failure rate.
Not to be confused w/ a 10 year review of all MYs over the last 10 years... then, in order to have a 20% failure rate you'd need to have the following (assume samples and sample sizes are same for each MY):
MY 2010 - 20% of all 2010s fail in 2010
MY 2009 - 10% failure of all 2009s fail in each year: 2009, 2010
MY 2008 - 6.66% failure of all 2008s fail in each year: 2008, 2009, 2010
MY 2007 - 5% failure of all 2007s fail in each year: 2007, 2008, 2009, 2010
MY 2006 - 4% failure of all 2006s fail in each year: 2006, 2007, 2008, 2009, 2010
MY 2005 - 3.33% failure of all 2005s fail in each year: 2005, 2006, 2007, 2008, 2009, 2010
MY 2004 - 2.85% failure of all 2004s fail in each year: 2004, 2005, 2006, 2007, 2008, 2009, 2010
MY 2003 - 2.5% failure of all 2003s fail in each year: 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
MY 2002 - 2.22% failure of all 2002s fail in each year: 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
MY 2001 - 2% failure of all 2001s fail in each year: 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
Clearer?
Remember the old saying: "Statistics don't lie... but liars use statistics" ;)
Warm & fuzzier now? :)