There are two data sets x and y.
X includes = 14 25 19 35 20 12 5
Y includes = 360 293 315 212 315 331 404
to solve for the correlation coefficient, we need to get the following values step by step
Step 1: Find the mean of each set.
The mean of X = 18.571
The mean of Y = 318.571
Step 2: Subtract the mean of X from every value X value (denote this with letter a). Do the same for y (denote this with letter b).
The mean of X subtracted from every X value (a):
14 - 18.571 = -4.571
25 - 18.571 = 6.429
19 - 18.571 = 0.429
35 - 18.571 = 16.429
20 - 18.571 = 1.429
12 - 18.571 = -6.571
5 - 18.571 = -13.571
The mean of Y subtracted from every value of Y (b):
360 - 318.571 = 41.429
293 - 318.571 = -25.571
315 - 318.571 = -3.571
212 = 318.571 = -106.571
315 - 318.571 = -3.571
331 - 318.571 = 12.429
404 - 318.571 = 85.429
Step 3: Calculate: a * b, a^2 and b^2 of every value.
For a*b
-189.388
-164.388
-1.531
-1750.816
-5.102
-81.673
-1159.388
Sum: -3352.286
For a²
20.898
41.327
0.184
269.898
2.041
43.184
184.184
Sum: 561.714
For b²
1716.327
653.898
12.755
11357.469
12.755
154.469
7298.041
Sum: 21205.714
Step 4: Solve using this formula
r = ∑a * b / √((a²)(b²))
r = -3352.286 / √((561.714)(21205.714))
= -0.9713
The correlation coefficient is -0.971
