Note that the units are in miles. Write this problem down for yourself and make sure you understand how the units cancel out.
Question 2 -- How many cubic cm are in one cubic inch? [there are 2.54 cm in one inch]
Question 3 -- Therefore, one cubic centimeter equals ___________ cubic inches.
Question 4 -- What is the volume of the Earth in cubic inches _____________.
The density of the crust is about 2.6 and that of the mantle is about 3.2. Question 8 -- What does your calculation tell you about the density of the core?