An article suggests that a Poisson process can be used to represent the occurrence of structural loads over time Suppose the mean time between occurrences of loads is 0 4 year a How many loads can be expected to occur during a 4 year period loads b What is the probability that more than eleven loads occur during a 4 year period Round your answer to three decimal places c How long must a time period be so that the probability of no loads occurring during that period is at most 0 2 Round your answer to four decimal places yr You may need to use the appropriate table in the Appendix of Tables to answer this question