Which of the following is the most accurate definition of a function?

One of the inventors of integrated circuits observed that the number of transistors that fit on an integrated circuit will double every 24 months. what type of relationship most appropriately models this situation?

Which of these numbers of simulations of an event would be most likely to produce results that are closest to those predicted by probability theory? 15, 20, 5, 10

He weights of 2-pound bags of best dog food are approximately normally distributed with a given mean  and standard deviation  according to the empirical rule, what percentage of the bags will have weights within 3 standard deviations of the mean? 47.5%68%95%99.7%