To find Eric's relative error, we can use the formula for relative error:
\[ \text{Relative Error} = \frac{|\text{Measured Value} - \text{Actual Value}|}{|\text{Actual Value}|} \]
In this case, the measured value is \(3.91\) inches and the actual value is \(4\) inches.
- Calculate the absolute error:
\[ |\text{Measured Value} - \text{Actual Value}| = |3.91 - 4| = |-0.09| = 0.09 \]
- Now calculate the relative error:
\[ \text{Relative Error} = \frac{0.09}{4} \]
- Perform the division:
\[ \frac{0.09}{4} = 0.0225 \]
- Finally, to express the relative error as a percentage (which is common practice), multiply by 100:
\[ 0.0225 \times 100 = 2.25% \]
Thus, Eric's relative error, to the nearest hundredth, is \(0.0225\) (or \(2.25%\) when expressed as a percentage).