Friday, September 11, 2009

Rebuilding is Hard

Recently we observed the fourth anniversary of the Flood of New Orleans and Katrina's devastation of South Louisiana and the Mississippi Gulf Coast. A lot is still left to be done.

Freedom Tower

Today is the eighth anniversary of the attacks on the World Trade Center on September 11, 2001.

The Freedom Tower construction is continuing yesterday;
  • Steel installation (two cranes on site)
  • 24 jumbo steel columns are being installed to form the tower's base perimeter
  • Both the south and north cores now above grade
  • Final concrete installation on the sub-grade structure, including the surrounding plaza
  • Utility installation and tie-ins
  • Crews are coordinating substructure construction while maintaining PATH service
1 World Trade Center (formerly the Freedom Tower) is the center piece of the redevelopment of Ground Zero. It will include 2.6 million square feet of office space, retail space and a subway station. Scheduled for completion in by the end of 2013 work on the tower began April 27, 2006.

ΣΣΣΣΣΣ The Bell Curve

I always thought that 6σ was derived from the math for 6 Standard Deviations on a Normal Distribution. That works out to 1 in 506,800,000.
zσ percentage within CI percentage outside CI ratio outside CI
68.2689492% 31.7310508% 1 / 3.1514871
1.645σ 90% 10% 1 / 10
1.960σ 95% 5% 1 / 20
95.4499736% 4.5500264% 1 / 21.977894
2.576σ 99% 1% 1 / 100
99.7300204% 0.2699796% 1 / 370.398
3.2906σ 99.9% 0.1% 1 / 1000
99.993666% 0.006334% 1 / 15,788
99.9999426697% 0.0000573303% 1 / 1,744,278
99.9999998027% 0.0000001973% 1 / 506,800,000
99.999 999 999 7440% 0.0000000002560% 1 / 390,600,000,000