My wife just called and said that, by chance, she decided to go home for lunch to walk the dog and the Fedex truck pulled up. I guess that ends this little experiment. Roll credits...

The probability of the sub running into my wife exactly on the 5th try: 8.2%

The probability of it happening within the first 5 attempts: 67%

Number of attempts it would take to get above 95% probability of successful lunch-time delivery: 15

Expected value E(x), number of attempts before delivery is expected: 5

Number of people who normally go home for lunch in the DC area: about 0

Typical commute, DC area: 1.5 hours

Having a new sub to setup when I get home: PRICELESS.