Earthquakes For a recent period of 100 years, there were 93 major earthquakes (at least 6.0 on the Richter scale) in the world (based on data from the World Almanac and Book of Facts). Assuming that the Poisson distribution is a suitable model, find the mean number of major earthquakes per year, then find the probability that the number of earthquakes in a randomly selected year is

a. 0

b. 1

c. 2

d. 3

e. 4

f. 5 g. 6 h. 7 Here are the actual results: 47 years (0 major earthquakes); 31 years (1 major earthquake); 13 years (2 major earthquakes); 5 years (3 major earthquakes); 2 years (4 major earthquakes); 0 years (5 major earthquakes); 1 year (6 major earthquakes); 1 year

(7 major earthquakes). After comparing the calculated probabilities to the actual results, is the Poisson distribution a good model?

4-5 Beyond the Basics