1. Why can we not use first differences when we have independent cross sections in two years (as opposed to having panel data)

Antonio made a scale model of a building. the model's scale is 1 inch to 235 feet and its height is 3.5 inches. what is the exact height of the actual building? enter your answer in the box.

The variable in a relation who’s value depends on the value of the independent variable is called what?

The given diagram shows the parts of a right triangle with an altitude to the hypotenuse. using the two given  measures, find the other four.