Advertisements
Advertisements
Question
Calculate the coefficient of correlation from the following data:
∑X = 50, ∑Y = – 30, ∑X2 = 290, ∑Y2 = 300, ∑XY = – 115, N = 10
Advertisements
Solution
∑X = 50, ∑Y = – 30, ∑X2 = 290, ∑Y2 = 300, ∑XY = – 115, N = 10
Coefficient of correlation
r(X, Y) = `("N"sum"XY" - (sum"X")(sum"Y"))/(sqrt("N"sum"X"^2 - (sum"X")^2) xx sqrt("N"sum"Y"^2 - (sum"Y")^2))`
= `(10(-115) - (50)(-30))/(sqrt(10(290) - (50)^2) xx sqrt(10(300) - (-30)^2))`
= `(-1150 + 1500)/((20)(sqrt2100))`
= `350/((20)(45.83))`
= `350/916.6`
r = 0.382
APPEARS IN
RELATED QUESTIONS
In the following data one of the value of y is missing. Arithmetic means of x and y series are 6 and 8 respectively. `(sqrt(2) = 1.4142)`
| x | 6 | 2 | 10 | 4 | 8 |
| y | 9 | 11 | ? | 8 | 7 |
Estimate missing observation.
Find the coefficient of correlation for the following:
| X | 78 | 89 | 96 | 69 | 59 | 79 | 68 | 62 |
| Y | 121 | 72 | 88 | 60 | 81 | 87 | 123 | 92 |
The variable which influences the values or is used for prediction is called
The person suggested a mathematical method for measuring the magnitude of linear relationship between two variables say X and Y is
The coefficient of correlation describes
Find the coefficient of correlation for the following data:
| X | 35 | 40 | 60 | 79 | 83 | 95 |
| Y | 17 | 28 | 30 | 32 | 38 | 49 |
Calculate the correlation coefficient from the following data:
∑X = 125, ∑Y = 100, ∑X2 = 650, ∑Y2 = 436, ∑XY = 520, N = 25
A measure of the strength of the linear relationship that exists between two variables is called:
If the points on the scatter diagram indicate that as one variable increases the other variable tends to decrease the value of r will be:
The value of the coefficient of correlation r lies between:
