# Hi guysIn my statistics book there is an example. They say that we

• Niles
In summary, the conversation discusses the significance level in statistics and its relation to probability and the null hypothesis. The example given shows a difference of 4 occurrences between the observed and expected values, which is significant at the 1% level. The significance level is a way of determining the probability of an event happening by chance and in this case, the small probability of the observed result makes it a significant event. The significance level should not be interpreted as the probability of an event happening by chance from the null hypothesis, but rather as a measure of how significant the observed result is.
Niles
Hi guys

In my statistics book there is an example. They say that we see 3 occurrences of type A, and theoretically expect 7. This is a difference of 4, since we know that the standard deviation is 1.65 (they calculate it), then the difference is 2.4 standard deviations. Looking at a table of the Gaussian, this is significant at the 1% level.

My question is regarding the significance at the 1% level. What is it they mean by that statement?

If indeed the theoretical expectation is 7 with standard deviation 1.65, then of course it is possible that you get only 3 occurrences in any real experiment.
If you calculate the theoretical probability of actually observing this, you will see that it is very small. So if something with such a small probability does happen, this can hardly be a coincidence, and it is a significant event.
The significance level is just a mathematically sound way of saying what the term very small in the previous paragraph means. For example, taking a significance level of 1%, you consider any probability below 1% as very small (and therefore, if you actually observe such an event when you only run the experiment once or twice, it is significant).

That does make sense, thank you. I was viewing the significance level (SL) in the light of the null hypothesis. I always understood SL as being the probability that the event happened by chance from the null hypothesis. But in this example, the 3 occurrences of type (our null hypothesis) cannot "accidentally" yield 7 occurrences. So does this mean that my interpretation is wrong?

## 1. What is the meaning of "Hi guys"?

"Hi guys" is a common greeting used to address a group of people, typically used in informal or casual settings.

## 2. Can "Hi guys" be used for both men and women?

Yes, "guys" is often used as a gender-neutral term and can be used to address a mixed group of people.

## 3. Is "Hi guys" considered appropriate in all situations?

No, "Hi guys" may be considered informal and may not be appropriate in more formal or professional settings.

## 4. Are there any alternative phrases to "Hi guys"?

Yes, there are many other common greetings that can be used to address a group, such as "Hello everyone" or "Hey everyone."

## 5. Is it necessary to use the word "guys" when saying "Hi guys"?

No, the word "guys" can be replaced with other terms such as "folks" or "friends" to address a group of people in a similar manner.

• Set Theory, Logic, Probability, Statistics
Replies
1
Views
1K
• Set Theory, Logic, Probability, Statistics
Replies
3
Views
333
• Set Theory, Logic, Probability, Statistics
Replies
4
Views
1K
• Set Theory, Logic, Probability, Statistics
Replies
5
Views
1K
• Set Theory, Logic, Probability, Statistics
Replies
2
Views
1K
• Set Theory, Logic, Probability, Statistics
Replies
26
Views
3K
• Set Theory, Logic, Probability, Statistics
Replies
21
Views
2K
• Set Theory, Logic, Probability, Statistics
Replies
12
Views
1K
• Set Theory, Logic, Probability, Statistics
Replies
5
Views
2K
• Set Theory, Logic, Probability, Statistics
Replies
9
Views
1K