1. A particular concentration of a chemical found in polluted water has been found to be lethal to fish that are exposed to the concentration for 24 hours. When exposed, only 70% of the fish will survive. Twenty fish are placed in a tank containing this concentration of chemical in water. (a) (1 pt) Which distribution is being described in this problem? Explain your decision. (b) (1 pt) Find the probability that exactly 13 survive. (c) (1 pt) Find the probability that at most 16 survive. (d) (1 pt) Find the probability that at least 10 survive. (e) (2 pts) Find the mean and standard deviation of the number that survive. (Round the standard devia- tion to 5 decimal places.)