45.7 Degrees Fahrenheit.
Since the temperature lowers by 1.1 degrees F every 1000 feet, the temperature will drop 8 times the amount of 1.1 degrees since the plane will reach 8,000 feet above ground assuming it starts at ground level, so 8*1.1=8.8 so we then can subtract 8.8 degrees from the starting temperature of 54.5 since the temperature would be dropping instead of rising, which then would give you 54.5-8.8=45.7
