Working out the cumulative distribution

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SUMMARY

The discussion focuses on deriving the cumulative distribution function (CDF) for the maximum value \(X_{max}\) of a continuous random variable defined by the probability density function \(f(x) = \frac{3x^2}{C^3}\) for \(0 < x < C\). It establishes that \(G(a) = P(X_{max} \le a)\) can be expressed as the product of probabilities for each individual sample item, specifically \(G(a) = P(X_1 \le a) \cdot P(X_2 \le a) \cdots P(X_n \le a)\). The independence of the sample values is crucial for this formulation, allowing for the simplification of the cumulative distribution calculation.

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millwallcrazy
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f(x) = 3(x^2)/(C^3) 0 < x < C
= 0 otherwiseLet the mean of the sample be Xa and let the largest item in the sample be Xm. What is the cumulative distribution for Xm?
 
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I'm assuming that you are to work with a random sample of size n.

Note that for ANY continuous random variable, if X_{max} is the maximum value, you know that X_{max} \le a means that EVERY item in the sample is \le a, so that

<br /> G(a) = P(X_{max} \le a) = P(X_1 \le a \text{ and } X_2 \le a \text{ and } \dots \text{ and } X_n \le a)<br />

Now, knowing that the X values are independent (since they're from a random sample), what can you do with the statement on the right?
 

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