Advertisements
Advertisements
प्रश्न
Find the coefficient of correlation for the following:
| Cost (₹) | 14 | 19 | 24 | 21 | 26 | 22 | 15 | 20 | 19 |
| Sales (₹) | 31 | 36 | 48 | 37 | 50 | 45 | 33 | 41 | 39 |
Advertisements
उत्तर
| X | Y | x = `"X" - bar"X"` = X − 20 |
y = `"Y" - bar"Y"` = Y − 40 |
x2 | y2 | xy |
| 14 | 31 | − 6 | − 9 | 36 | 81 | 54 |
| 19 | 36 | − 1 | − 4 | 1 | 16 | 4 |
| 24 | 48 | 4 | 8 | 16 | 64 | 32 |
| 21 | 37 | 1 | − 3 | 1 | 9 | − 3 |
| 26 | 50 | 6 | 10 | 36 | 100 | 60 |
| 22 | 45 | 2 | 5 | 4 | 25 | 10 |
| 15 | 33 | − 5 | − 7 | 25 | 49 | 35 |
| 20 | 41 | 0 | 1 | 0 | 1 | 0 |
| 19 | 39 | − 1 | − 1 | 1 | 1 | 1 |
| 180 | 360 | 0 | 0 | 120 | 346 | 193 |
N = 9, ∑X = 180, ∑Y = 360, ∑x2 = 120, ∑y2 = 346, ∑xy = 193, `bar"X" = (sum"X")/"N" = 180/9` = 20, `bar"Y" = (sum"Y")/"N" = 360/9` = 40.
Correlation coefficient (r) = `(sum"xy")/(sqrt(sum"x"^2 sum"y"^2))`
r = `193/sqrt (120 xx 346)`
r = 0.947
APPEARS IN
संबंधित प्रश्न
Calculate the coefficient of correlation for the ages of husbands and their respective wives:
| Age of husbands | 23 | 27 | 28 | 29 | 30 | 31 | 33 | 35 | 36 | 39 |
| Age of wives | 18 | 22 | 23 | 24 | 25 | 26 | 28 | 29 | 30 | 32 |
If the values of two variables move in the opposite direction then the correlation is said to be
Correlation co-efficient lies between
The correlation coefficient is
The variable which influences the values or is used for prediction is called
Scatter diagram of the variate values (X, Y) give the idea about
The coefficient of correlation describes
If Cov(x, y) = – 16.5, `sigma_"x"^2` = 2.89, `sigma_"y"^2` = 100. Find correlation coefficient.
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 coefficient of correlation from the following data:
∑X = 50, ∑Y = – 30, ∑X2 = 290, ∑Y2 = 300, ∑XY = – 115, N = 10
