Advertisements
Advertisements
Question
The correlation coefficient from the following data N = 25, ∑X = 125, ∑Y = 100, ∑X2 = 650, ∑Y2 = 436, ∑XY = 520
Options
0.667
− 0.006
– 0.667
0.70
Advertisements
Solution
0.667
Explanation:
r = `("N"sum"XY" - sum"X"sum"Y")/(sqrt("N"sum"X"^2 - (sum"X")^2) sqrt("N"sum"Y"^2 - (sum"Y")^2))`
= `(25(520) - 125 xx 100)/(sqrt(25 xx 650 - (125)^2) sqrt(25 xx 436 - (100)^2))`
= `(13000 - 12500)/(sqrt(16250 - 15625) sqrt(10900 - 10000))`
= `500/(sqrt625 sqrt900)`
= `500/(25 xx 30)`
= `2/3`
= 0.6666
= 0.667
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.
Example for positive correlation is
If the values of two variables move in same direction then the correlation is said to be
If the values of two variables move in the opposite direction then the correlation is said to be
If r(X,Y) = 0 the variables X and Y are said to be
From the following data, N = 11, ∑X = 117, ∑Y = 260, ∑X2 = 1313, ∑Y2 = 6580, ∑XY = 2827 the correlation coefficient is
The variable whose value is influenced (or) is to be predicted is called
The variable which influences the values or is used for prediction is called
If r = – 1, then correlation between the variables
Calculate the Karl Pearson Correlation Co-efficient for the following data:
| Demand for Product X: | 23 | 27 | 28 | 29 |
30 |
31 | 33 | 35 | 36 | 39 |
| Sale of Product Y: | 18 | 22 | 23 | 24 | 25 | 26 | 28 | 29 | 30 | 32 |
