Q.1. Plot the following data asa a scatter diadram and comment over the result :

X : 1110 15 13 10 16 13 8 17 14

Y : 67 99 7 11 9 6 1211

Q.2. From the following data compute the product moment corralation between x and y .

x series y series

Arithmetic mean 25 18

square of deviations from arithmetic mean136 138

Q.3. Calculate karl pearsons cofficient of corralation on the following data :

x : 1518 21 24 27 3036 39 42 48

y : 25 25 27 27 3133 35 41 4145

Q.4. Calculate correlation cofficient between x, the number of raniy days per month and y , the number of rain coats sold in that month in a certain shop for 12 month . interpret the results .

X : 14 8 18 10 22 9 3 5 6 11 13 13

Y : 15 11 20 12 15 7 3 4 7 10 11 29

Q.5. The deviations from their means of two series (x and y) are given below :

x : -4 -3 -2 -1 0 +1 +2 +3 +4

y : +3 -3 -4 0 +4 +1 +2 -2 -1

Q.6. Find suitable coefficient of correlation for the following data :

Fertilizers used (in tons) : 15 18 20 24 30 35 40 50

Productivity (in tons) : 85 93 95 105 120 130150 160