From the following information determine coefficient of correlation between X and Y series.

X SERIES :

No. of items = 15

Mean = 25

S.D. = 3.01

Sum of squares of deviation from Mean = 136

Sum of product of deviations of X and Y from their respective means = 122

Y SERIES :

No. of items = 15

Mean = 18

S.D. = 3.03

Sum of squares of deviation from mean = 138

Sum of product of deviations of X and Y from their respective means = 122