America’s largest airlines have approved a $4 round-trip fare hike, despite anxiety over Ebola and higher travel prices for the upcoming holiday season. The hike suggests that the airline industry believes demand for air travel is so strong that passengers won’t be discouraged by an Ebola scare or slight increase, an analyst said. The fare hike, the first successful across-the-board increase in six months, was initiated Thursday by Delta. American, US Airways, Southwest, and United matched the increase Friday. The hike comes as the industry is reporting record earnings, thanks to growing demand and sliding fuel costs.