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**4littlepiggiesmom****Member**- Registered: 2006-01-09
- Posts: 42

1. Suppose a fair coin is tossed 7 times. How many ways are there to get exactly three heads or three tails? I got B

Answer choices-

a. 7

b. 21

c. 35

d. 210

e. None of theese

2. Suppose three fair dice are thrown. What is the probabliity that the top faces will sum to 6?

a. 1

b. 1/6

c. 1/216

d. 5/108 MY ANSWER

e. Non of the these

Am I getting the right answer or do I need to redo it...again? K

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**George,Y****Member**- Registered: 2006-03-12
- Posts: 1,306

c: 7 6 5/(3 2 1)=35

d: right (diceA diceB diceC) = (1 1 4), (1 4 1), (4 1 1), (1 2 3), (1 3 2), (2 1 3), (2 3 1), (3 1 2), (3 2 1), (2 2 2) ;Prob=(3+6+1)/(6 6 6)

*Last edited by George,Y (2006-03-13 15:28:12)*

**X'(y-Xβ)=0**

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**4littlepiggiesmom****Member**- Registered: 2006-01-09
- Posts: 42

Thanks so much~

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**George,Y****Member**- Registered: 2006-03-12
- Posts: 1,306

You r welcome

**X'(y-Xβ)=0**

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