1.23: Show that (n , n_1,n_2,n_3,....,n_k ,)=(n-1 , n_1-1,n_2,n_3,....,n_k ,)+(n-1 , n_1,n_2-1,n_3,....,n_k


Problem 1.23: Show that

\(\left( \begin{matrix}

n \\

{{n}_{1}},{{n}_{2}},{{n}_{3}},....,{{n}_{k}} \\

\end{matrix} \right)=\left( \begin{matrix}

n-1 \\

{{n}_{1}}-1,{{n}_{2}},{{n}_{3}},....,{{n}_{k}} \\

\end{matrix} \right)+\left( \begin{matrix}

n-1 \\

{{n}_{1}},{{n}_{2}}-1,{{n}_{3}},....,{{n}_{k}} \\

\end{matrix} \right)+...+\left( \begin{matrix}

n-1 \\

{{n}_{1}},{{n}_{2}},{{n}_{3}},....,{{n}_{k}}-1 \\

\end{matrix} \right)\)

Problem 1.19:

  1. Compute
    \(\left( \begin{matrix}
    \frac{1}{2} \\
    4 \\
    \end{matrix} \right)\)
    and
    \(\left( \begin{matrix}
    -3 \\
    3 \\
    \end{matrix} \right)\)
  2. Approximate \(\sqrt{5}\) using Stirling’s approximation.

Problem 5.1: If X has a discrete uniform distribution \(f(x)=\frac{1}{k}\), for \(x=1,2...,k\), show that

  1. The mean is \(\mu =\frac{k+1}{2}\)
  2. Its variance is \({{\sigma }^{2}}=\frac{{{k}^{2}}-1}{12}\).

Problem 5.2 If X has a discrete uniform distribution \(f(x)=\frac{1}{k}\), for \(x=1,2...,k\), show that its moment generating function is given by:

\[{{M}_{X}}(t)=\frac{{{e}^{t}}(1-{{e}^{kt}})}{k(1-{{e}^{t}})}\]

Problem 5.6

  1. Consider the probability function defined by
    \[f(x)=\left\{ \begin{aligned}
    & \theta \text{ if }x=1 \\
    & 1-\theta \text{ if }x=0 \\
    \end{aligned} \right.\]
    Compute \(E\left( X \right)\) and \(\operatorname{var}\left( X \right)\) .
  2. Define \(Y=\sum\limits_{i=1}^{n}{{{X}_{i}}}\), compute \(E\left( Y \right)\) and \(\operatorname{var}\left( Y \right)\) .

Problem 5.14:

  1. Prove that
    \(M_{X-\mu }^{(k)}(t)=E\left( {{(X-\mu )}^{k}}{{e}^{t(X-\mu )}} \right)\)
  2. For a binomial distribution with parameters n and p, prove that its variance is

\(np(1-p)\)

Problem 5.20: For a probability function defined by

\(p(n)=\theta {{(1-\theta )}^{n-1}}\)

Compute the moment generating function.

Problem 5.23: Prove the "memoryless property" of the geometric distribution. This is, prove that

\(\Pr (X=x+n|X>n)=\Pr (X=x)\)

Price: $11.81
Solution: The downloadable solution consists of 9 pages, 281 words.
Deliverable: Word Document


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