Astudy has three groups, each with an equal number of participants. you can estimate the population variance from the variance within each group, giving three estimates, 54.4, 48.6, and 50.9. what is the within-group estimate of the population variance?

a

step-by-step explanation:

a

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