Solving Random Variable x | Maria Seeking Help

AI Thread Summary
Maria is seeking help with a statistics question related to random variables and variance. She has completed part (i) of the problem but is struggling with part (ii). The discussion includes a formula for variance, V(S), which is defined as E(S²) - E(S)², and notes that V(S) must be greater than zero for S to be considered random. Additionally, it is mentioned that the expected value E(S) must be less than the standard deviation σ. The conversation emphasizes the importance of understanding these statistical concepts to solve the problem effectively.
maria69
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Hi if someone can please help me to this question? PLease?
Thank you
maria
http://img21.imageshack.us/img21/9793/statistikh4.jpg
 
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Please define S!
 


Sorry i forgot to mention what S is. Here:
http://img682.imageshack.us/img682/3866/question4.jpg
i have done part (i) but i can't do part (ii)
Can you please help??
Thank you
Maria
 
Last edited by a moderator:


V(S)=E(S2)-E(S)2
E(S2)=σ2
V(S) must be > 0, otherwise S would not be random.
Therefore E(S) must be < σ.
 

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