Page 320 - DMTH404_STATISTICS

Statistics

Notes 13. Compute Karl Pearson's coefficient of correlation from the following data :

X : 8 11 15 10 12 16
Y : 6 9 11 7 9 12

14. Calculate Karl Pearson's coefficient of correlation between the marks obtained by 10
students in economics and statistics.

Roll No. : 1 2 3 4 5 6 7 8 9 10
Marks in eco. : 23 27 28 29 30 31 33 35 36 39
Marks in stat. : 18 22 23 24 25 26 28 29 30 32

15. Find Karl Pearson's coefficient of correlation from the following data and interpret its
value.

Wages (Rs) : 100 101 103 102 100 99 97 98 96 95
Cost of Living (Rs) : 98 99 99 97 95 92 95 94 90 91
16. Find the coefficient of correlation between X and Y. Assume 69 and 112 as working origins
for X and Y respectively.
X : 78 89 96 69 59 79 68 61
Y : 125 137 156 112 107 136 123 108

17. The distribution of population (in thousand) and blind persons according to various age
groups is given in the following table. Find out correlation between age and blindness.

Age groups : - 0 10 10 -20 20 -30 30 -40 40 -50 50 -60 60 -70 70 -80
Population : 100 60 40 36 24 11 6 3
No. of Blind : 55 40 40 40 36 22 18 15

18. Find out the coefficient of correlation from the following data :

X : 300 350 400 450 500 550 600 650 700
Y : 1600 1500 1400 1300 1200 1100 1000 900 800

19. Calculate the coefficient of correlation of the following figures relating to the consumption
of fertiliser (in metric tonnes) and the output of food grains (in metric tonnes) in a district.
Comment on your result.
Chemical Output of Chemical Output of
Fertiliser used food grains Fertiliser used food grains
100 1000 170 1360
110 1050 180 1420
120 1080 190 1500
130 1150 200 1600
140 1200 210 1650
150 1220 220 1650
160 1300 230 1650

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