According to the Mendelian theory of inheritance of genes, offspring of a dihybrid cross of peas could be any of the four types: round-yellow [RY], wrinkled-yellow (IVY), round-green (RG) and wrinkled-green (VKG), and their probabilities are in the ratio 9:3:3:1.
(a) If X denotes the number of RY offspring from 130 such crosses, find the mean and standard deviation of X.
(b) If Y denotes the number of WG offspring from 85 such crosses, find the mean and standard deviation of V.