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2 votes
Please Help me

QUESTION 9
x
0246
8
10
12
24
14
*****
y
9
9
10
11
11
12
13
13
I
[1.5 darks] Given the (x, y)-data as shown in Table below
Find the best line model for the data
and find the correlation coefficient r.
Solution. Please write your
detailed solution here, You can
also put some needed information
in the Table above:

Please Help me QUESTION 9 x 0246 8 10 12 24 14 ***** y 9 9 10 11 11 12 13 13 I [1.5 darks-example-1
asked
User Khurshid
by
8.3k points

1 Answer

4 votes

Answer:

To find the best line model for the data, we will use linear regression analysis.

First, we need to calculate the mean of x and y:

mean of x = (0 + 2 + 4 + 6 + 8 + 10 + 12 + 24 + 14) / 9 = 8

mean of y = (9 + 9 + 10 + 11 + 11 + 12 + 13 + 13 + 14) / 9 = 11

Next, we need to calculate the deviations of x and y from their respective means:

deviation of x = x - mean of x

deviation of y = y - mean of y

x y deviation of x deviation of y (deviation of x)^2 deviation of x * deviation of y

0 9 -8 -2 64 16

2 9 -6 -2 36 12

4 10 -4 -1 16 4

6 11 -2 0 4 0

8 11 0 0 0 0

10 12 2 1 4 2

12 13 4 2 16 8

24 13 16 2 256 32

14 14 6 3 36 18

Then, we can calculate the slope (b) of the best-fit line using the formula:

b = sum of (deviation of x * deviation of y) / sum of (deviation of x)^2

b = (16 + 12 + 4 + 0 + 0 + 2 + 8 + 32 + 18) / (64 + 36 + 16 + 4 + 0 + 4 + 16 + 256 + 36) = 0.190

Next, we can calculate the y-intercept (a) of the best-fit line using the formula:

a = mean of y - b * mean of x

a = 11 - 0.190 * 8 = 7.48

Therefore, the equation of the best-fit line is:

y = 0.190x + 7.48

Finally, we can calculate the correlation coefficient (r) using the formula:

r = sum of (deviation of x * deviation of y) / (sqrt(sum of (deviation of x)^2) * sqrt(sum of (deviation of y)^2))

r = (16 + 12 + 4 + 0 + 0 + 2 + 8 + 32 + 18) / (sqrt(64 + 36 + 16 + 4 + 0 + 4 + 16 + 256 + 36) * sqrt(16 + 16 + 1 + 0 + 0 + 1 + 4 + 4 + 1)) = 0.905

Therefore, the best-fit line for the given data is y = 0.190x + 7.48, and the correlation coefficient is r = 0.905.

Explanation:

answered
User David Steiman
by
8.0k points
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