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1999 FIU/Florida Poll

© Institute for Public Opinion Research
School of Journalism and Mass Communication
Florida International University

Hurricane Floyd Evacuation: FIU/Florida Poll

return to index file Hurricane Floyd Evacuation: FIU/Florida Poll

AREA ESTIMATED 1999 NUMBER OF HOUSEHOLDS PROPORTION OF SAMPLE HOUSEHOLDS THAT EVACUATED SAMPLE SIZE ESTIMATED NUMBER OF HOUSEHOLDS EVACUATING (population of HH * proportion) MARGIN OF ERROR (plus or minus percent)1 95% confidence that this is lowest number evacuating2 95% confidence that this is highest number evacuating2 EST. NUMBER OF PEOPLE EVACUATING (# of households * 2.46)3
Statewide 6,222,543 0.126 1,201 782,360 1.9% 767,690 797,031 1,924,607
North 452,602 0.368 95 166,748 9.7% 150,573 182,922 410,199
Central 835,528 0.268 189 223,955 6.3% 209,812 238,098 550,929
South to Broward 1,052,029 0.122 223 128,632 4.3% 123,101 134,162 316,434
Miami-Dade 897,612 0.064 170 57,743 3.7% 55,614 59,873 142,049

HOUSEHOLDS TAKING IN EVACUEES -- STATEWIDE 6,222,543 0.052 1,201 325,377 1.3% 321,280 329,473 800,427

NOTES

Note 1: The margin of error is relative to the proportion of the sample. Thus if .122 of the sample evacuated and the margin of error is .018, the 95% confidence highest proportion of the population evacuating in .122+.018=.140. The lowest is .122-.018=.104. The formula used for margin of error of a proportion is:
1.96 * the square root of: ( proportion * (1-proportion) / sample size ) )
Note that when the proportion gets very large or very small, the margin of error gets less (i.e. the measurement of the proportion becomes more precise). This is because the sample of respondents is much less variable in their response. For example, in Miami-Dade County only 11 out of 170 respondents answering the evacuation question did evacuate. This means Miami-Dade residents did not show much variation in evacuation (94% did not), so the estimate is quite accurate (±3.7%).

Note 2: 95% confidence means that if 100 studies were done like this one, 95% percent of them would report a proportion in the same range.

Note 3: This gives an approximate estimate of number of persons.


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