Standard deviation question

[Bones920]

How do I calculate my standard deviation if I just play tourneys? Read Gambling Theory and other topics pg 62. Do I still need 30 observations? How often do I need to recompute? Does the number of players, buy-in, blind structure, or being online effect the numbers? How do you know when its time to move up in higher buy-ins? How do I calculate how much I'll need for my tourney play? Also read, Poker Gaming and Life pg. 139. Is your wallet fat enough for tourneys? How do I plug my numbers into that formula playing many different tourneys I.E. $33 buy-in with 21 players or $6 buy-in with 75 players or $6 buy-in with 674 players? How does mathematical expectation figure into tourney play? How do swings figure into tourney play? Will I be able to use the same formulas for sit-in-goes (STT) as I do for multi-table tourneys (MTT)?