All Questions
11
questions
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Calculating the final sum of an investment with a specific daily growth of rate over a period of time.
Calculating the final sum of an investment with a specific daily growth of rate over a period of time.
I do apologize if this question is very basic for the vast majority of people in this forum but ...
- 3
1
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2
answers
51
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Given $n=8$ and $\sum x=552$ and $\sum x^2=48000$, calculate $S^2=\frac{\sum x^2}{n}-\bar{x}^2$
In my statistics textbook there is the following exercise:
For $n=8$ and $\sum x=552$ and $\sum x^2=48000$ calculate $S^2=\frac{\sum x^2}{n}-\bar{x}^2$.
I'm coming from a probability background so I'...
- 1,979
0
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1
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31
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Likelihood ration Algebraic issue
I have got the following likelihood:
$$l(p) = C + xlog(p) + (n-x)log(1-p)$$
I have got that $\theta_0 = 1/3$ and $\theta_1 = 1/2$
All I need to do is find the correct value of the log likelihood ...
- 149
1
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4
answers
94
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1
vote
2
answers
78
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Exanding the a summation squared
I am reviewing a proof as part of a courser course on regression, but I am getting hung up on some intermediate steps.
The proof we are working is a proof that Y-bar (the average of the individual Y ...
- 219
0
votes
3
answers
159
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calculate double sum
I have the following.
$\sum_{x=1}^n \sum_{i = 1}^x \frac{2}{n(n+1)}$
Hint from Milton book first $n$ integers have the sum $\frac{(n+1)n}{2}$
This is for verifiying that it it's a valid joint ...
- 149
1
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0
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160
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How to isolate and solve for k in a Sigma notation probability mass function equation?
"isolate and solve for k:"
$$P(X = k) = \sum_{k=0}^n {{{K \choose k} {{N-K} \choose {n-k}}}\over {N \choose n}}$$
If the above equation is a function of P, how would the equation be stated as a ...
- 11
6
votes
4
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198
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How to determine the number removed from the list [duplicate]
One number is removed from a set of integers from 1 to n,the average of the remaining numbers is $\large{\frac{163}{4}}$. Which number was removed?
I tried to find the mean of $$\frac{1+2+....+n-1}{n-...
1
vote
1
answer
30
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How can i simplify the following term to get the right side?
$$\sum_{h=1}^{L}\frac{W_h^2S_h^2}{n_h}=\frac{1}{n}\sum_{h=1}^{L}{(W_hS_h)}^2$$
where,
$n_h=\frac{n}{\sum_{h=1}^{L}N_hS_h}N_hS_h$ $\quad\text{and}\quad$ $W_h=\frac{N_h}{N}$ $\quad\text{and}\quad$ $\...
- 1,457
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2
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A small calculation .
How
$\sum_{k=0}^n (-1)^n\times(-1)^{n-k}=\sum_{k=0}^n(-1)^k$
i got it
$\sum_{k=0}^n(-1)^n\times(-1)^{n-k}=\sum_{k=0}^n(-1)^{2n-k}$
And
is that $\mathbb E[\mathbb E(X)]=\mathbb E(X)$ ?
- 1,457
4
votes
4
answers
10k
views
How $\frac{1}{n}\sum_{i=1}^n X_i^2 - \bar X^2 = \frac{\sum_{i=1}^n (X_i - \bar X)^2}{n}$
How
$\frac{1}{n}\sum_{i=1}^n X_i^2 - \bar X^2 = \frac{\sum_{i=1}^n (X_i - \bar X)^2}{n}$
i have tried to do that by the following procedure:
$\frac{1}{n}\sum_{i=1}^n X_i^2 - \bar X^2$
=$\frac{1}{...
- 1,685