Forensic scientists can determine the approximate height that a male person was by measuring the length of the femur (thigh bone). They use the formula: height = 1.88f + 32.01, where f is the length of the femur in inches.

To the nearest inch, how many inches long is the femur of a male who is 71 inches tall?

166 inches
21 inches
20 inches
165 inches

1 answer

To find the length of the femur for a male who is 71 inches tall using the formula provided, we can rearrange the formula \( \text{height} = 1.88f + 32.01 \) to solve for \( f \).

Starting with the original equation:

\[ \text{height} = 1.88f + 32.01 \]

Substituting the height (71 inches) into the equation:

\[ 71 = 1.88f + 32.01 \]

Next, we will isolate \( f \) by first subtracting 32.01 from both sides:

\[ 71 - 32.01 = 1.88f \]

\[ 38.99 = 1.88f \]

Now, divide both sides by 1.88 to solve for \( f \):

\[ f = \frac{38.99}{1.88} \]

Calculating this gives:

\[ f \approx 20.74 \]

To the nearest inch, the length of the femur is approximately \( 21 \) inches.

Therefore, the correct answer is:

21 inches