Interval data is like ordinal except we can say the intervals between each value are equally split. The most common example is temperature in degrees Fahrenheit. The difference between 29 and 30 degrees is the same magnitude as the difference between 78 and 79 (although I know I prefer the latter).
Bethlehem is a city in Lehigh and Northampton counties in the Lehigh Valley region of the eastern portion of the U.S. state of Pennsylvania. As of the 2010 census, the city had a total population of 74,982, making it the seventh largest city in Pennsylvania, after Philadelphia, Pittsburgh, Allentown, Erie, Reading, and Scranton.
Together with Allentown and Bethlehem, the Valley embraces the Allentown-Bethlehem-Easton metropolitan area, including Lehigh, Northampton, and Carbon counties within Pennsylvania, and Warren County in the adjacent state of New Jersey.