Each sample of water has a 10% chance of containing a particular organic pollutant. Assume that the samples are independent with regard to the presence of the pollutant. Find the probability that in the next 15 samples: (i) Exactly 2 contain the pollutant. (ii) At least three samples contain the pollutant. (iii) Determine the probability that the number of pollutants is between 1 and 3, inclusive. (iv) Calculate the mean and standard deviation of the probability distribution function. (15 marks)