The table given below, containing part of data collected by Parkes from herd-book records of Duroc-Jersey Pigs, shows the distribution of sex in litters of 4, 5, 6 and 7 pigs. Examine whether these data are consistent with the hypothesis that the number of males within a litter of given size is a binomial variable, the sex ratio being independent of litter size. If you are not altogether satisfied with this hypothesis, in what direction or directions does it seem to fail?

No. of males Size of litter in litter 4 5 6 7 0 1 22 3 1 14 20 16 21 2 3 4 5 6 7 Totals 38 23 41 53 63 14 35 78 117 1 14 53 104 4 18. 46 21 2 53 116 221 374 (Lond. B.Sc.)