Assume that different groups of couples use a particular method of gender selection and each couple gives birth to one baby. This method is designed to increase the likelihood that each baby will be a girl, but assume that the method has no effect, so the probability of a girl is 0.5. Assume that the groups consist of 19 couples. Complete parts (a) through (c) below. <: a. find the mean and standard deviation for numbers of girls in groups births. value is u="E." an integer or a decimal. do not round.>