Question

Lesson

Cool Down: Off by a Little Bit?
Clare
estimates that her brother is 4 feet tall. When they get measured at the doctor's
office, her brother's height is 4 feet, 2 inches.
1. Should Clare's or the doctor's measurement be considered the actual height?
Explain your reasoning.
2. What was the error, expressed in inches?
3. What was the error, expressed as a percentage of the actual height?

Answer 1

• See below

Explanation:

Given

• Estimated value - 4 feet,
• Measured value - 4 feet, 2 inches

Solution

1. The measured height is the exact value therefore it is to be considered as actual height.

2. The error is the difference between actual and estimated values:

• 4 feet 2 inches - 4 feet = 2 inches

3. Percent error is:

• Error / Actual value * 100%

or

• 2 in / 4 ft, 2 in *100% =
• 2 in / (4*12 + 2) in * 100% = convert ⇒ 1 foot = 12 inches
• 2 in / 50 in * 100% =
• 4%