Question

Correlation Coefficients. If the formula _____ were used to find the r-value of the following data, what would be the value of y?

A. 5
B. 9.
C. 7
D. 3

Answer 1

Answer: 0.9839

Explanation:

X Values

∑ = 15

Mean = 3

∑(X - Mx)2 = SSx = 10

Y Values

∑ = 35

Mean = 7

∑(Y - My)2 = SSy = 50

X and Y Combined

N = 5

∑(X - Mx)(Y - My) = 22

R Calculation

r = ∑((X - My)(Y - Mx)) / √((SSx)(SSy))

r = 22 / √((10)(50)) = 0.9839

Meta Numerics (cross-check)

r = 0.9839

Answer 2

C. 7

Explanation:

According to the problem, we have to find
`y` which refers to the mean of y-values.

So, we just have to find the mean:

`y=(3+5+6+9+12)/(5)=(35)/(5)=7`

Therefore, the right answer is C.

Remember that the mean is defined as the quotient betwene the sum of all values, and the total number of them. In this case, the sum is 35 and the total number is 5.