Pl answer following question

According to the Canadian census of 2006, the median annual family income for families in Nova Scotia is$56,400. Consider a random sample of 24 Nova Scotia households.

a. What is the expected number of households with annual incomes less than $56,400?

b. What is the standard deviation of households with incomes less than $56,400?

c. What is the probability of getting at least 18 out of the 24 households with annual incomes under $56,400?