Foot / Feet

[jack]

Are these correct? If not, why?
1. He is about five foot five. (What does 'five foot five' mean?)
2. He is about five feet five. (If 'feet' is wrong here, why?)

3. He is about five feet. (Correct? If #2 is incorrect, why is #3 correct?)
4. He is about five foot. (Incorrect? If this is incorrect, why is #1 correct?)

[Casiopea]

Are these correct? If not, why?
1. He is about five foot five. (What does 'five foot five' mean?)
2. He is about five feet five. (If 'feet' is wrong here, why?)

3. He is about five feet. (Correct? If #2 is incorrect, why is #3 correct?)
4. He is about five foot. (Incorrect? If this is incorrect, why is #1 correct?)

1. He is about five-foot-five. (Numerically,5'5")
2. He is about five-feet, five-inches tall. (5'5")
3. He is about five-feet tall. (5')
4. He is about five-foot (something). (5'?")