An airline uses many different types of airplanes. Information regarding some of the airplanes is given in the table below. A 5-column table with 5 rows. Column 1 is labeled Plane with entries SkyBus 280, SkyBus 580, Grigson A-2, Grigson A-5, SkyDancer. Column 2 is labeled Number of seats with entries 120, 225, 70, 130, 350. Column 3 is labeled Seat width (inches) with entries 20.3, 20.6, 19.9, 20.5, 20.2. Column 4 is labeled Wi-fi with entries no, yes, no, yes, yes. Column 5 is labeled first-class seats question mark with entries no, yes, no, no, yes.

Which of the variables is a continuous variable?

number of seats
seat width
Wi-Fi
first-class