A political analyst sampled 8,000 voting records from each of four counties. Of the samples, County A had 5,254 voters who voted in the last election, County B had 4,583, County C had 5,368, and County D had 4,396. The mean from the four counties is 4,900, with a standard deviation of 483. What is the total sample proportion of people who voted in these counties? 0.6125

0.4907

0.4893

0.3875

geometry: triangles

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call the larger triangle abc

then the smaller triangle cde is similar to abc (all angles are equal, aaa).  

ab is the side that is 36, and we wish to find de, the side corresponding to ab

area_cde = area_abc - area_cde --> area_abc / area_cde = 2

let x=length of de

ratio of areas = (ratio of sides)^2

+2+=+%2836%2fx%29%5e2+

+2+=+1296%2fx%5e2+

++x%5e2+=+1296%2f2+=+648+

25.45584