Chapter 1: Problem 12
Let \(X\) be a random variable such that \(R(t)=E\left(e^{t(X-b)}\right)\) exists
for \(t\) such that \(-h
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Chapter 1: Problem 12
Let \(X\) be a random variable such that \(R(t)=E\left(e^{t(X-b)}\right)\) exists
for \(t\) such that \(-h
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Let a random variable \(X\) of the continuous type have a pdf \(f(x)\) whose graph is symmetric with respect to \(x=c\). If the mean value of \(X\) exists, show that \(E(X)=c\) Hint: Show that \(E(X-c)\) equals zero by writing \(E(X-c)\) as the sum of two integrals: one from \(-\infty\) to \(c\) and the other from \(c\) to \(\infty\). In the first, let \(y=c-x\); and, in the second, \(z=x-c .\) Finally, use the symmetry condition \(f(c-y)=f(c+y)\) in the first.
Two distinct integers are chosen at random and without replacement from the first six positive integers. Compute the expected value of the absolute value of the difference of these two numbers.
A mode of a distribution of one random variable \(X\) is a value of \(x\) that
maximizes the pdf or pmf. For \(X\) of the continuous type, \(f(x)\) must be
continuous. If there is only one such \(x\), it is called the mode of the
distribution. Find the mode of each of the following distributions:
(a) \(p(x)=\left(\frac{1}{2}\right)^{x}, x=1,2,3, \ldots\), zero elsewhere.
(b) \(f(x)=12 x^{2}(1-x), 0
A coin is tossed two independent times, each resulting in a tail (T) or a head (H). The sample space consists of four ordered pairs: TT, TH, HT, HH. Making certain assumptions, compute the probability of each of these ordered pairs. What is the probability of at least one head?
If \(X\) is a random variable such that \(E(X)=3\) and \(E\left(X^{2}\right)=13\), use Chebyshev's inequality to determine a lower bound for the probability \(P(-2<\) \(X<8)\)
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