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Old June 6th, 2009, 04:24 AM
db5vry db5vry is offline
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Default Continuous Random Variable question. Could you help?

The continuous random variable X has probability density function f given by
f(x) = \frac{6}{5}x (x - 1), for 1 \leq x \leq 2
f(x) = 0, otherwise.
a] Evaluate E\frac{1}{X}.
b] Find an expression for the cumulative distribution function.
c] Evaluate P(X \leq 1.75).
d] State, with a reason, whether the median of X is greater or less than 1.75.

For part a] I calculated E(X) which I found to be , so E(1/X) was done by which is 10/17, or 0.58 or something like that. Is this right?

For part b] I had .

For c] if P(X 1.75) is F(1.75), then that should be 0.30625 if part b] is correct,

and to answer d] you can say that the median of X must be greater than 0.5 because the value of 1.75 is not greater than 0.5.

Am I right or did something go wrong?
Thanks for any help
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