1. Suppose there are 3 plane crashes every year. Using the Poisson probability distribution, what would be the probability that there will be only one plane crash next month? (Enter your answer in decimal format with 4 digits after the decimal point).
2. It is reported that 25% of American households use a cell phone exclusively for their telephone service. In a sample of sixteen households, what is the expected number of households that exclusively using cell phones. (Round your number to the nearest whole number, if necessary)
3. It is reported that 27% of American households use a cell phone exclusively for their telephone service. In a sample of sixteen households, find the probability that exactly 4 households exclusively use a cell phone for telephone service.(Enter your answer in decimal format with 4 digits after decimal point.)