Find the (a) mean, (b) variance, and (c) standard deviation of the binomial distribution for the given random variable, and (d) interpret the results. Sixty-three percent of U. S. mothers with school-age children choose fast food as a dining option for their families one to three times a week. You randomly select five U. S. mothers with school-age children and ask whether they choose fast food as a dining option for their families one to three times a week. The random variable represents the number of U. S. mothers who choose fast food as a dining option for their families one to three times a week.