A human hair has a diameter of about 4×10^−3 inches. A fingernail is about 0.011 inches thicker. How thick is a fingernail? Write your answer as a decimal to 3 places.
First, let's convert the human hair diameter from scientific notation to a decimal to work with both measurements in the same format:
A human hair diameter = 4×10^−3 inches
= 0.004 inches
You've stated that a fingernail is 0.011 inches thicker than the human hair diameter. To find the thickness of a fingernail, we'll add the thickness of a human hair to this additional thickness:
Fingernail thickness = Human hair diameter + Additional thickness
= 0.004 inches + 0.011 inches
= 0.015 inches
The thickness of a fingernail is 0.015 inches when written as a decimal rounded to three places.