The difference between linear correlation and linear regression in statistics

The difference between linear correlation and linear regression in statistics

There are three main differences: 1. Linear correlation analysis involves the close degree of linear relationship between variables. Linear regression analysis is to establish a linear model between variables on the basis of linear correlation between variables. 2. Linear regression analysis can be controlled and predicted by regression equation, but linear correlation analysis can not

What does regression mean statistically
What is the purpose of regression analysis in statistics? Must regression equation be established?

More than 100 years ago, a British geneticist (Galton) noticed that when a father is very tall, his son's height is generally not higher than his father's height. Similarly, if a father is very short, his son is generally not shorter than his father's height, and will be close to the average of ordinary people. At that time, the British geneticist called this phenomenon regression, Now this concept extends to the trend that random variables tend to concentrate on regression lines
But the closer to the regression line, the more the observed values are, and the less the observed values deviate from the farther ones. This phenomenon, which is not completely functional, but also has a certain number of relationships, is called regression. Regression can be divided into linear regression and nonlinear regression
Regression analysis is to understand and predict the observed values, and get the results by calculating and estimating the coefficients of regression equation
Generally speaking, linear regression needs to establish regression equation

The general term formula an = 3N + 1 of sequence {an} is known. The second term, the fourth term and the eighth term are taken out in turn. The second ^ n term constitutes a new sequence {BN},
Find the general formula of {BN}

Because the general term formula of sequence {an} is an = 3N + 1, the second term, the fourth term and the eighth term are taken out in turn
In this way, n only gets all even terms
So n = 2K, K is a positive integer
So BK = 3 * 2K + 1 = 6K + 1, K is a positive integer
So BN = 6N + 1, n is a positive integer

The length of the three sides of a triangle is ABC, which satisfies the equation A & sup2; - 16b & sup2; - C & sup2; + 6ab + 10bc = 0 to find a + C = 2B?

a^2-16b^2-c^2+6ab+10bc
=a^2-16b^2-c^2+8ab-2ab+8bc+2bc+ac-ac
=(a^2+ac-2ab)+(8ab+8bc-16b^2)+(-ac-c^2+2bc)
=a(a+c-2b)+8b(a+c-2b)-c(a+c-2b)
=(a+c-2b)(a+8b-c)
Because ABC is a triangle with three sides
a+8b-c>a+b-c>0
So a + c-2b = 0
a+c=2b

The square of junior high school mathematics from 1 to 30

1*1=1
2*2=4
3*3=9
4*4=16
5*5=25
6*6=36
7*7=49
8*8=64
9*9=81
10*10=100
11*11=121
12*12=144
13*13=169
14*14=196
15*15=225
16*16=256
17*17=289
18*18=324
19*19=361
20*20=400
21*21=441
22*22=484
23*23=529
24*24=576
25*25=625
26*26=676
27*27=729
28*28=784
29*29=841
30*30=900

I use the ^ sign for square
1.（xy^+3)（xy^+3）-2x（-x+y）
2.(x+2)(x^+4)(x-2)
3. Simplify first, then evaluate
(x ^ y ^ - 4) (- x ^ y ^ - 4) - 4 (XY-1 / 2) * (XY-1 / 2) where x = 1, y = - 2
Why don't you answer the first question

Question 2: = (x ^ 2-4) (x ^ 2 + 4) = x ^ 4-16
Question 3: = (16-x ^ 4Y ^ 4) - 4 (x ^ 2Y ^ 2 + 1 / 4-xy)
=16-X^4Y^4-4X^2Y^2-1-4XY
=-(X^2Y^2-2)^2+19-4XY
When x = 1, y = - 2, the original =. Is simple

What is the arithmetic square root of the square of junior high school mathematics (- 1 / 4)

It's one fourth

A junior high school mathematics problem about what the square
（a-b）(a²+ab+b²) -a²b+ab²=(a-b)²
————————
three
Finding the value of A-B
Wait for answers online

（a-b）(a2+ab+b2) ———————— -a2b+ab2=(a-b)23（a-b）(a2+ab+b2) ————————- -ab（a－b）=(a-b)23（a-b）【(a2+ab+b2) -3ab】—————————————=(a-b)23（a-b）(a2 -2ab+b2）———————...

Junior high school mathematics a (1-A) plus (a + 1) Square-1

a(1-a)+(a+1)2-1=a-a2+a2+2a+1-1=3a

The negative quadratic power of 5

5^(-2)
=1/(5²)
=1 / 25 (1 / 25)
Do not understand welcome to ask~