It is reported that 25% of American households use a cell phone exclusively for their telephone service. In a sample of twelve households, find the probability that: a.No household uses a cell phone as their exclusive telephone service. (Round your answer to 4 decimal places.) Probabilityb.Exactly 6 households exclusively use a cell phone for telephone service. (Round your answer to 4 decimal places.) Probabilityc.Find the mean number of households exclusively using cell phones. (Round your answer to 4 decimal places.) Mean