as of July 2004 the population of the United States 293,027,71 if more then half of this people live within 80 kilometers of the ocean about how many people live within that distance?

Probably missing one digit at the end of the population. I will add a zero.

Half=50% = 0.5
More than half of the people, N, live withing 80 of the ocean
N = 293027710 * 0.5 approx. = ?

Can you continue from here?