probability – A sample size $ n = $ 80 is derived from a population size $ N $. The size of the sample is divided into two parts.

A sample size $ n = $ 80 is drawn from a population of size $ N $. The size of the sample is divided into two parts and the samples are drawn independently of the two parts. One quarter of the sample is extracted by SRSWOR. The sample proportions of the two samples are calculated. The proportion of the population is estimated at the arithmetic mean of the two samples. proportions of the sample. Discover the variance of this estimator of the proportion of the population.

Suppose the population is divided into two parts, one having a characteristic $ A $ and one not having $ A $.

In the question, it is stated that the estimate of the proportion of the population $ hat {P} = frac { bar {y_1} + bar {y_2}} {2} $ or $ bar {y_1}, bar {y_2} $ are respectively the averages of the samples from the two samples where $ y_ {ij} = 1 text {if} j ^ {th} text {the unit is in the same sample} $ or $ i = $ 1.2.
Now we need to know $ V ( bar {y_1}) $ and $ V ( bar {y_2}) $ but for that we need to know the proportion of characteristic population $ A $. But this is not given. Please help!

What is the reason why America is so divided?

The policy has ALWAYS been split. Hell, some of our founders killed themselves in DUELS. There were fist fights on the floor of the congress.

However, I think we are witnessing a period when both parties AND THEIR ELECTORS are moving further and further away from the center. I have three main causes.

1) Computer-aided supporter Gerrymandering. There is nothing new in partisan gerrymandering. The difference is that computers and demographics mean that it is now possible for consultants to draw hyper-accurate maps to get VERY specific election results. General elections are therefore safer than ever. Holders who almost always lose do so during their primaries. SCOTUS has recently passed, and I can not blame the legal logic. But it's a big problem, and both parties are doing it.

Secure general elections and threatening primaries mean that the average politician is only threatened by his extreme flank. They do not have to worry about a centrist threat. Thus, they become more extreme in order to invoke the main competitors.

2) McCain-Feingold and other campaign finance reforms. Whenever someone talks to you about withdrawing money from politics, you should hit him in the mouth. Each reform of campaign funding has made the incumbents more secure, and the most important has been McCain-Feingold (MF).

MF's main contribution was to eliminate Soft Money, which consisted of making donations to parties rather than to candidates, and then to the parties that were paying this money. Because it lacked a hood, unlike Hard Money (intended for candidates), advocates of campaign reform claimed it was a source of corruption. It was a lie.

Soft money has almost always been spent by the party on behalf of CHALLENGERS, not holders. The incumbents have an advantage in terms of money and notoriety and do not usually need help. The parties usually spent money for their challengers. Soft Money, in other words, made elections MORE COMPETITIVE. That is why the companies in place hated the soft money.

3) modern media. Let's face it, the media in America have never been as good as we sometimes think. Yellow journalism and the use of newspapers to personally attack vendettas are as old as the very existence of the printing press. Maybe older.

But what has changed is that at one point, people have developed their trust in journalists. A misplaced faith. And the industry has been fragmented and rundown since then. Now, everyone chooses his source of information to confirm his own prejudices. Liberals only listen to liberal sources, Conservatives only read conservative sources.

And in all sources, journalistic responsibility has disappeared. The time of each article requiring two or more RELIABLE sources to be printed is over. Now, even the slightest rumor goes straight to the air. Being FIRST is more important than being TRUE. And retractions are rarely made, and never in evidence. It is not uncommon for opinion to pose as journalism and too many viewers do not know where one ends or the other ends.

Because people choose their own sources to reflect their biases, most people live in echo chambers where they do not even hear the opposite ideas presented in their original form … instead from this, they will at best hear opposing ideas presented in an inclined pejorative form that does not guarantee anybody can find a ground of understanding.


magento2 – Order divided according to the source or location in M2.3

Background information:

I'm working on a Magento 2.3 solution with a Click & Collect system, where c & c sites have their own inventory and where a product can be purchased online (shipping costs) or c & c (no shipping costs).

I know that M2.3 has a Click & Collect feature, but as I understand from the documentation, this feature allows you to select a location where the customer will get all the products.

The system I am working on requires a different configuration. Customers can buy a product online (the product will be shipped) or a product click & collect (the product is already in the physical store), or both, and it is necessary to create different orders. This is an example of the workflow, if it is an order mixed with an online product and a click & collect product:

Contents of the cash register: -> Payment of the customer -> Order WEB001:
- Product 1
- Product 1 (online) - Product 2
- Product 2 (online) - Shipping costs
- Product 3 (c & c)
Order CC001:
- Product 3

I'm thinking of configuring it with the help of multi-source inventory of M2.3 (MSI), which also makes it easier to set up stock inventory for locations, but I'm not sure if it's easy. have a few questions to ask:

First question: Is it possible to configure / code M2.3 to create a command with a specific prefix code based on the source of a product?

Second question: In case of mixed control, is it possible to configure / code M2.3 to split the command (creation of several commands) according to the source of the products?

Third question: In case of mixed order, the customer pays the total that he sees at checkout with the selected payment method (eg PayPal). Since the order will be split, how does the payment work? Will be made several transactions? Or just a transaction and Magento divides the amount paid based on total orders?

I do not have any code to show because I am working on the feasibility of the project but I lack information in the official documentation. So I'm asking here if anyone has worked or has any idea of ​​how the system should work to achieve this type of workflow.

Thank you!

Why do the Liberals act as if the country was not already divided when Trump took office?

No, sorry, it's YOUR reaction to Obama that has pushed the division. It was YOU who went around the hanging in effigy, it is YOU who joked about the fact that he has a stamp of watermelon and fried chicken on the lawn of the White House, it is YOU who compared her husband, wife and daughters. It is YOU who promised to make him a president with a mandate, even before taking office. It was you who claimed that he was not a citizen. It was YOU who attacked him for doing exactly what you praised GW Bush. You must not blame Obama for what YOU have done. You are rude and fanatical ignorant who practiced the race without stopping for 8 years. He got stuck in your craw, a black bourgeois elected president, instead of "knowing in his right place". GFY. You are not lamentable, you are despicable, you should be ashamed of yourself, but you are not. You are proud to be like that. You are a shame for the United States.

But the division goes back further than that. It really started with Rush Limbaugh in the '80s, then Newt Gingrich in the' 90s – the idea that the Democrats were not just a loyal political opposition, but also an "enemy". YOU @ssholes started it all, then have the balls to try to take care of ourselves.

You are the one who does not have a clue.


algorithms – Count the number of ways in which the numbers 1, 2, …, n can be divided into two sets of equal sum

count the number of ways in which the numbers 1,2, …, n can be divided into two sets of equal sums.

This is my recursive algorithm, what's wrong here ?:

int f (int sum, int i) {// sum is the current sum, i is the current indx (<=n)
    if(i>not) {
return ((2 * sum) == (n * (n + 1) / 2)); // ie sum == totalsum / 2
int cnt = f (sum, i + 1) + f (sum + i, i + 1); // go to i + 1 or add i to sum, then go to i + 1
return cnt;
For example, if n = 7, there are four solutions:
{1,3,4,6} and {2,5,7}
{1,2,5,6} and {3,4,7}
{1,2,4,7} and {3,5,6}
{1,6,7} and {2,3,4,5}
let f (0,1) = 7

The answer is f (0,1) for all n (n is defined globally)

Thank you!

How are the three channels of an ISDN line separate? And how does this differ from the way channels are divided into DSL lines?

  • My thought is (correct me if I'm wrong) an ISDN line has two B
    for data transfer and a Canal D for signaling;
    The channels of a DSL line are separated by the frequencies of the electromagnetic waves (for example, 0 ~ 4 kHz for telephone calls).
  • So the question
    is how are the channels of an ISDN line separated of each of them?
    And how does this differ from the way the channels are separated in a DSL?

Wide screen monitor divided into 2 false screens for the system

I want to buy a widescreen (50 inches) but I want to know if I can split the screen into 2/3 fake screen (for Windows / Linux or even Macos) (with software or hardware).
The first and third fake screens will each have 1/4 and the second (central screen) will have 2/4 of the total screen.

(Like this image:

Algorithms – Group the numbers so that they are getting closer to their total divided by two

Given a set of numbers, I would like to find an algorithm that divides them into two groups, so that the sum of the numbers in each group is as close as possible to half the sum of all the numbers, which means that I am looking for two groups whose sums are as close as possible to each other.

For example, given the table [120, 100, 33, 57], the goal would be

(120 + 100 + 33 + 57) / 2 = 155

The subgroups closest to this number are [120, 33] and [100, 57]because they give a sum of 153 and 157respectively for a distance of 2 of purpose. If we had to go with for example [120, 57] and [100, 33], their distance from 22 the goal would be a little bigger and therefore less ideal.

Another example:

table = [44, 18, 71, 109, 29]
objective = 135.5
subgroups = [[109, 29], [44, 18, 71]]distance = 2.5

Is there a way to do that, in addition to forcing it brutally?

Hoew can I combine the files divided and created by WinRAR in the original file (compressed zip package, I think)?

I have several file folders created by WinRAR, I believe. These are files that exist in groups of 3, with the extensions .0, .1 and .IDX.

I have old data that, in my opinion, are old pictures or old movies. I'm sure I separated them with WinRAR playing with it. I recently discovered the old files and I hoped to be able to check them. They could keep good memories if I could recompile them.

Thank you for any help.

Sum of the number divided by its GCD


Given a formula:


GCD (x, y) means the GCD (greatest common divisor) of x and y.

For example: if N = 2, then:

  • f (2) = 1 / GCD (1, 4) + 2 / GCD (2, 4) + 3 / GCD (3, 4) + 4 / GCD (4.4)
  • f (2) = 1/1 + 2/2 + 3/1 + 4/4
  • f (2) = 1 + 1 + 3 + 1
  • f (2) = 6

Given N, find f (N)!

Simplified formula that I found using Wolframalpha, finding the first 10 elements: (4 ^ (n + 1) + 8) / 12


#define MOD 1000000007
using namespace std;
typedef short i16;
typedef unsigned short u16;
typedef int i32;
typedef unsigned int u32;
typedef long int i64;
typedef unsigned long int u64;
typedef float f32;
typedef double f64;

u64 pawa (u64a, u64b) {
u64 tot = 1;
for (u64 i = 0; i < b; i++) {
        tot *= a;
        tot = tot % MOD;
    return tot;

int main(){
    u64 n;
    cin>> n;
cost << (pawa (4, n + 1) + 8) / 12 << & nbsp ;;
returns 0;

I have implemented these codes above and still get time limit exceeds. The constraint of the upper corner is 10 ^ 9. How can I improve my algorithm? Can you give me a hint or something?

Problem link: