Calculating Variances of Functions of Sample Mean

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The discussion focuses on finding the asymptotic distributions of functions of the sample mean Y from a random iid sample. For Y^2, it converges in probability to u^2, with variance V(Y^2) calculated as σ^4 + 2σ^2u^2, leading to Y^2 being normally distributed. For 1/Y, it converges to 1/u, with the variance needing clarification, but the delta method was ultimately recalled to solve the problem. The participants confirm their understanding of the calculations and the application of the delta method for variance. Overall, the thread emphasizes the importance of asymptotic analysis in statistics.
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1. Essentially what I'm trying to do is find the asymptotic distributions for
a)
Y2
b) 1/Y and
c) eY where
Y = sample mean of a random iid sample of size n.
E(X) = u; V(X) = σ2

Homework Equations


a) Y^2=Y*Y which converges in probability to u^2,

V(Y*Y)=\sigma^4 + 2\sigma^2u^2

So, \sqrt{n}*(Y^2 - u^2) converges in probability to N(0,\sigma^4 + 2\sigma^2u^2)

So, Y^2\sim N(u^2,\frac{\sigma^4 + 2\sigma^2u^2}{n})

Is that right?
b) \frac{1}{Y} converges in probability to \frac{1}{E(X)} = \frac{1}{u}
V(\frac{1}{x}) = \frac{1}{σ^2} ??

Thus,
\sqrt{n}(\frac{1}{Y} - \frac{1}{u}) converges in distribution to N(0,V(\frac{1}{x})*\frac{1}{n})
What is V(1/X) ?Am I on the right track?
 
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Solved. Just had to remember the delta method.
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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