Earthquakes can be broken into two classes based on the directions the earth moves when they fracture. The classes can be compared across time, for whether earthquakes occur in a given region in a...

Earthquakes can be broken into two classes based on the directions the earth moves when they fracture. The classes can be compared across time, for whether earthquakes occur in a given region in a small time period, and if they occur in the next small time period, and it can be added up across several time periods, below is a table for a region off Indonesia over a 30 year period Is happening of an earthquake in one time period statistically independent of happening in another time period? Test at the .01 level (10 points) These are earthquakes of the same type, Which cells have higher than expected occurrence if independence is true. (Use the deviation table). (10 points) Second time period, earthquake happens Second time period no earthquake happens Marginal Sums First time period, Earthquake happens 148 274 422 First time period no earthquake happens 276 2626 2902 Marginal sums 424 2900 3324


QUIZ 8 1) Earthquakes can be broken into two classes based on the directions the earth moves when they fracture. The classes can be compared across time, for whether earthquakes occur in a given region in a small time period, and if they occur in the next small time period, and it can be added up across several time periods, below is a table for a region off Indonesia over a 30 year period Is happening of an earthquake in one time period statistically independent of happening in another time period? Test at the .01 level (10 points) These are earthquakes of the same type, Which cells have higher than expected occurrence if independence is true. (Use the deviation table). (10 points) Second time period, earthquake happens Second time period no earthquake happens Marginal Sums First time period, Earthquake happens 148 274 422 First time period no earthquake happens 276 2626 2902 Marginal sums 424 2900 3324 2) The earthquake chart is the same chart, only comparing when earthquakes of different types follow one another Are they statistically independent now (.01 level again) (8 points) How do the deviations from expectation under independence differ from the chart in problem 3 (hint look at the pattern of pluses and minuses) (8 points) If you think about what each cell means, what do these differences mean in terms of the way the two types of earthquakes interact (4 points) Second time period, earthquake happens Second time period no earthquake happens Marginal Sums First time period, Earthquake happens 5 314 319 First time period no earthquake happens 314 2691 3005 Marginal sums 319 3005 3324