Question

The table below represents the closing cost of ABC for the last 5 days. What is the r -value of the linear regression that fits these data?
Day Value
1 20.71
2 19.69
3 19.61
4 19.64
5 19.26

Choices are as follows
A. -0.79631
B. 0.86493
C. 0.91237
D. -0.85650

Answer 1

Answer: -0.94719

Step-by-step explanation:

Answer 2

Answer:

The correct option is D.

Step-by-step explanation:

The linear regression equation is in the form of

$y=bx+a$

Where,

$b=\frac{n(\sum xy)-(\sum x)(\sum y)}{n(\sum x^2)-(\sum x)^2}$

$a=\frac{(\sum y)(\sum x^2)-(\sum x)(\sum xy)}{n(\sum x^2)-(\sum x)^2}$

The formula of r is

$r=\frac{n(\sum xy)-(\sum x)(\sum y)}{\sqrt{[n(\sum x^2)-(\sum x)^2][n(\sum y^2)-(\sum y)^2]}}$

The values are

$\sum x=15,\sum y=98.91,\sum x^2=55,\sum y^2=1957.8295,\sum xy=293.78, n=5$

Using above formula, we get

$r=-0.85650$

Therefore option D is correct.