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Unformatted text preview: y seats, with populations greater than 2,500, will tend to be distributed uniformly one to a cell, while all other urban places will be randomly distributed and follow the Poisson model. Consequently, large county seata are distributed with a density p which is, by definition, restricted to values between 0 and 1, while all other urban places are distributed with a density Dacey has shown that the distribution which satisfies these assumptions, such that the probability that a specified county contains x towns 24 If y and p are unknown their values may be given by the following moments estimates (55) (56) Notice that as p approaches 0, indicating that all county seats have populations less than 2,500, the first term in (52) tends to the Poisson distribution with a mean equal to y, while the second term tends to 0 and vanishes. Alternatively, as p tends to 1 the model's variance/mean ratio, (54)/(53), becomes increasingly smaller to indicate that the predicted frequency array is representing an increasingly more uniform pattern. This model has been found to fit the frequency distribution of Iowa towns for all U.S. census periods between...
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 Summer '08
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 Geography, The Land

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