Second time period, Second time period no Marginal Sums earthquake happens earthquake happens First time period, 5 314 319 Earthquake happens First time period no 314 2691 3005 earthquake happens Marginal sums 319 3005 3324 Are they statistically independent now (.01 level again) How do the deviations from expectation under independence differ from the chart in problem 3 (hint look at the pattern of pluses and minuses) If you think about what each cell means, what do these differences mean in terms of the way the two types of earthquakes interact