Range, variance and standard deviation all describe the dispersion of sample data. Why is it more scientific to use standard deviation to describe the dispersion of sample data?

Range, variance and standard deviation all describe the dispersion of sample data. Why is it more scientific to use standard deviation to describe the dispersion of sample data?

In fact, variance and standard deviation express the same meaning. Standard deviation means how much each data deviates from the average value of this group of data. It can also see the representativeness of the average value of this group. If the standard deviation is larger, the representativeness of the average value will be smaller; otherwise, it will be larger

If a certain data is exactly all integer solutions of absolute value 1-3a ≤ 14, then the standard deviation of the sample data is
Absolute value 1-3a ≤ 14 means absolute value 1-3a ≤ 14

-14 ≤ 1-3a ≤ 14 get such a ∈ {- 4, - 3, - 2, - 1,0,1,2,3,4,5} mean AI = 5 / 10 = 0.5. I don't know whether your standard deviation is the population standard deviation or the sample standard deviation, that is, divide by N in the formula, or divide by (n-1) the population standard deviation (divided by n) = {[(- 4.5) ^ 2 + (- 3.5) ^ 2 + (-)

How much does college mathematics have to do with high school mathematics
I'm going to study in TVU. I'm a junior high school student. I don't know if I want to understand college mathematics. Do I have to understand all high school mathematics,

Well, I can only say that it's good to study in high school, but it's not necessarily that if high school doesn't study in University, there will be no law school. The systems of University and high school are totally different in ideology. For example, higher mathematics is mainly about calculus, which is the idea of taking the limit and then seeking the sum. High school doesn't involve it, so it can't completely study high school mathematics, but

What are the ways to compare sizes

Difference method, ratio method, median method, image method

How bad is math to me

It doesn't matter. You can basically add, subtract, multiply and divide, and you can recognize 1234. Anyone who comes from junior high school or high school can make money. As long as you are willing to work, have a bright mind, and have never read a book, you can do it. The premise is to find a better master

Compare the size of √ 7-2 of 8 with that of 1 / 8 --- mathematics

The denominator is as big as the numerator
The size of 7-2 and 1
1=√9-2 > √7-2
The latter is larger

3-6 √ 5 and 3-5 √ 6
5 + 11 and 6 + 10

3-6 √ 5 and 3-5 √ 6
Square both sides to get 9-180 and 9-150
Obviously the big one on the right
5 + 11 and 6 + 10
Square both sides to get 16 + 2 √ 55 and 16 + 2 √ 60
√ 55 and √ 60 square meters
Get 55 and 60
So the big one on the right

How to compare the size of 2.1 ^ 1 / 2 and 2.2 ^ 1 / 2

Because 1 / 2 > 0
two point one

A mathematical comparison of the size of the problem
Compare the size: root 7-root 6 and root 5-2

√7-√6=1／（√7＋√6）
√5－2＝1（√5＋2）
Because √ 7 ＋ 6 ＞ 5 ＋ 2
So 1 / (√ 7 ＋ 6) ＜ 1 (√ 5 ＋ 2)
Namely: √ 7 - √ 6 ＜ 5-2

Compare the following logarithms!
-2 (- 4) and - | - 2 | - (- 4) and - | - 2|

-2 (- 4) = 2 * 4 = 8 - | - 2 | = - 2, so 8 is greater than - 2, so - 2 (- 4) is greater than - | - 2 | - (- 4) = 4 - | - 2 | = - 2, so 4 is greater than - 2, so - (- 4) is greater than - | - 2 | wuliangshou Buddha, Buddha says there is no end to the sea of bitterness, and you will come back to the shore! Benefactor, I see that you are a unique talent in the Wulin