18 Records of the Indian Museum. [Vol. XXIII, 



3^2 

 & = 3'6 o + ^- (1-50) = 0-9930 



500 



ft =3-54 75. \/57ai=: 0-9069 + ^ (-0861) 



1 1000 



= -9478 



Multiplying by X \ = '67449/^/71 = -04769 



we get, P.E. of ft = -045201. 



Then from Table XXXVIII, p. 71. 



ft* *°3 32 



ft = 3'5 \ZNSk~ 10-85 + |^(°'9) =ii-4458 



3-6 = 12-67 + — ( ro 7) = i3'37 8 3 



500 



47 5 

 For ft = 3'54 74, n'44 58 + ^^ (i"9325) 



\/N2z 2 = 12-3637 

 hence P.E. of ft= 5*89625 



From Table XI/I, p. 76. 



ft = 3 -5 VNt 8k = r 3 i _ ^(-02) = r 3 o 87 



3-6 132 - — x -02 = 1-31 87 



500 



ft=3'54 75> */N2ek= 1-3087 + ^- (-oi) = 1-3134 



P.E. of Skewness = -06 26 36 



We thus find 



Mean, M = r556'25 +3-2906 mm. 



S.D. "■ 69*00 ±26431 mm. 



Coeff. of V, V= 4-1660+ -1407 



The other constants are : — 



ft= -03 32 04 + -04 52 01 



ft. = 3"54 75 34 ±'58 96 25 



Skewness = sk= -06 98 58 + *o6 26 36 



We- thus find that the skewness is not significant: Hence we 

 are justified in assuming normal distribution, at least to a first 

 approximation. 



On this assumption we can find the P.E. of the moments 

 quite easily. 



