Teresa estimates that the height of a giraffe in a zoo is 18 feet. In fact, it is 16 feet tall. What is Teresa's percent error? Use proportional relationships to solve the problem. Be sure to show all of your work, provide your answer as a percentage, and round your answer to the nearest tenth.
The actual height of the giraffe is 16 feet, while Teresa estimated it to be 18 feet. To find the percent error, we need to first find the difference between the actual value and the estimated value.
Actual value - Estimated value = Difference in height
16 feet - 18 feet = -2 feet
Next, we need to find the absolute value of the difference in height to get rid of the negative sign.
|-2 feet| = 2 feet
To calculate the percent error, we divide the difference in height by the actual value, and then multiply by 100.
Percent Error = (|Difference in height| / Actual value) * 100
= (2 feet / 16 feet) * 100
= 0.125 * 100
= 12.5%
Therefore, Teresa's percent error is 12.5%.