Question

Amy measured the length of an eraser. She discovered that her accuracy in her measurement was off by 0.005 centimeters. Which of the following could be the measured length?

A. 325millimeters
B. 32.53millileters
C. 32.5milliliters
D. 32millileters

Answer 1

C. 32.5milliliters

Step-by-step explanation:

The margin of error is one-half the value of the last significant place.

Since the margin of error is 0.005 centimeter and the answer choices are in millimeters, convert the margin of error to millimeters.

0.005 cm × 10 = 0.05 mm

Since the margin of error is 0.05 millimeter, the last significant digit in her measurement will be in the tenths place, as shown below.

Therefore, 33.5 millimeters could be the measured length of the eraser.

Answer 2

Since the error 0.005 is measured to the nearest thousandth, the measurement is accurate to the nearest hundredth, so B. 32.53 mm.

If the error had been 0.05, then the measurement would be accurate to the nearest tenth, or 32.5 mm. An error of 0.5 corresponds to accuracy to the nearest 1, or 32 mm. Error of 5 is accuracy to the nearest ten.

The more exact the error, the more accurate the measurement. The measurement is 1 degree less than the error.