What is the diameter of the Earth in feet?

The diameter of the Earth is approximately 7,918 miles. To convert this measurement into feet, we need to multiply by the number of feet in a mile, which is 5,280. Therefore, when we calculate 7,918 miles multiplied by 5,280 feet per mile, the result is about 41.8 million feet. This conversion accurately reflects the size of the Earth, making 41.8 million feet the correct answer.

In the context of the other choices, options such as 30 million, 50 million, and 60 million are significantly off the mark when compared to the known diameter of the Earth. The correct answer aligns with scientific measurements and common knowledge about Earth's size.