Astronomers measure large distances in light-years. One light-year is the distance that light can travel in one year, or approximately 5,880,000,000,000 miles. Suppose a star is 13.4 light-years from Earth. In scientific notation, how many miles away is it?
a) 7.8792 1013 miles
b) 5.88 x 1015 miles
c) 1.34% 1012 miles
d)5.88 x 1012 miles