Final answer:
9,700,000 more people visited Blue Ridge Parkway than Great Smoky Mountains National Park in 2013.
Step-by-step explanation:
To find out how many more people visited Blue Ridge Parkway than Great Smoky Mountains National Park in 2013, we need to subtract the number of people who visited Great Smoky Mountains National Park from the number of people who visited Blue Ridge Parkway.
Blue Ridge Parkway was visited by about 1.9 x 107 (19,000,000) people and Great Smoky Mountains National Park was visited by about 9.3 x 106 (9,300,000) people.
Therefore, the difference is: 1.9 x 107 - 9.3 x 106 = 1.9 x 107 - 0.93 x 107 = 0.97 x 107 (9,700,000) people. So, 9,700,000 more people visited Blue Ridge Parkway than Great Smoky Mountains National Park in 2013.