The shell of the land snail Limocolaria martensiana has two possible color forms. streaked and pallid. In a certain population of these snails, 60% of the individuals have streaked shells. Suppose that a random sample of 10 snails is to be chosen from this population.
(1) What is the mean number of streaked-shelled snails?
(2) What is the standard deviation of the number of streaked-shelled snails?