If two similar triangular prisms have volumes of [tex]$512 \, \text{ft}^3$[/tex] and [tex]$1,331 \, \text{ft}^3$[/tex], find the scale factor.

A. [tex]\frac{64}{121}[/tex]
B. [tex]\frac{8}{11}[/tex]
C. [tex]\frac{4}{5}[/tex]
D. [tex]\frac{11}{12}[/tex]

Please select the best answer from the choices provided.



Answer :

Given two similar triangular prisms with volumes [tex]\(512 \text{ ft}^3\)[/tex] and [tex]\(1331 \text{ ft}^3\)[/tex], we need to find the scale factor between the prisms.

When dealing with similar three-dimensional shapes, the ratio of their volumes is equal to the cube of the ratio of their corresponding linear dimensions (such as edge lengths).

Let's denote the volumes of the two prisms by [tex]\( V_1 \)[/tex] and [tex]\( V_2 \)[/tex].

[tex]\[ V_1 = 512 \text{ ft}^3 \][/tex]
[tex]\[ V_2 = 1331 \text{ ft}^3 \][/tex]

The relationship between the volumes and the scale factor (let's call it [tex]\( k \)[/tex]) is given by:

[tex]\[ \left(\frac{\text{scale factor}}\right)^3 = \frac{V_2}{V_1} \][/tex]

Thus, we have:

[tex]\[ k^3 = \frac{1331}{512} \][/tex]

To find the scale factor [tex]\( k \)[/tex], we need to take the cube root of the ratio of the volumes:

[tex]\[ k = \sqrt[3]{\frac{1331}{512}} \][/tex]
[tex]\[ k = \left(\frac{1331}{512}\right)^{1/3} \][/tex]

Evaluating the cube root, we find that:

[tex]\[ k \approx 1.375 \][/tex]

Now, let us convert this decimal back to a fraction to find the corresponding answer from the provided choices.

The decimal 1.375 can be written as:

[tex]\[ 1.375 = 1 + 0.375 = 1 + \frac{3}{8} = \frac{8}{8} + \frac{3}{8} = \frac{11}{8} \][/tex]

The scale factor [tex]\( k \)[/tex] is therefore [tex]\( \frac{11}{8} \)[/tex].

Finally, to match it with the given answer choices, we take the reciprocal because the smaller to larger ratio is provided rather than the larger to smaller ratio. Thus, the answer is:

[tex]\[ \frac{8}{11} \][/tex]

So, the best answer from the choices provided is:

B. [tex]\(\frac{8}{11}\)[/tex]