Question 1062949
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The image of the dilated polyhedron is SIMILAR to the original polyghedron.


Coefficient of similarity {{{image/original}}} = {{{3/4}}}.


Hence the ratio {{{Volume_of_the_image/Volume_of_the_original}}} = {{{(3/4)^3}}} = {{{27/64}}}.


Then the Volume of the image is {{{21*(27/64)}}}.


Use your calculator.