who understands Least Squares Regressions

Question

amistre64 · Answer

manyof us do

anonymous · Answer

can you help me

amistre64 · Answer

spose you want to match some f(x) to a given set of known data points,  we can develop a system of partial derivatives from$$\sum(f(x_i)-y_i)^2$$
and find suitable coefficients to develop the regression equation with

amistre64 · Answer

youll have to give more information to narrow down what exactly you need help with tho

anonymous · Answer

Given the data points (1, 5), (3, 13), and (5, 21), which of the following equations describes the best-fit line?
  		A. 	y= -1 + 4x
  		B. 	y= 4 + 1x
  		C. 	y= 1 + 4x
  		D.     y= 2 + 4x

amistre64 · Answer

3 points .... well, we can work from memory to determine a slope and intercept

amistre64 · Answer

$$m=\frac{n\sum xy-\sum x\sum y}{n\sum xx-\sum x\sum x}$$
and you will use the avgX and avgY  to form a point slope form of the equation to deatl with

amistre64 · Answer

x^2  x  y     xy
 1    (1, 5)         5
 9    (3, 13)    39
25   (5, 21)  105
---------------
35   9   39    149

seems like the sums

amistre64 · Answer

$$m=\frac{3(149)-9(39)}{3(35)-9(9)}$$

and 9/3 = 3;  39/3 = 13  for the averages

amistre64 · Answer

looks to me to be:  y=4(x-3)+13

amistre64 · Answer

when the number of points becomes huge, excel works nice :)