A new trendy restaurant is growing exponentially. After being open for 11 months the restaurant was serving an average of 310 customers a day. By month 15, the restaurant was serving about 456 customers a day. Write an exponential function N(t) that models average number of customers, N after t months of being open. If necessary, round any values to four decimal places (do not round on intermediate steps). Write your answer in the form a(b)t.