1 A ratio variable, has all the properties of an interval variable, and also has a clear definition of 0.0. 2  When the variable equals 0.0, there is none of that variable. 3  Variables like height, weight, enzyme activity are ratio variables.4  Temperature, expressed in F or C, is not a ratio variable. A ordinal variable, is one where the order matters but not the difference between values. 2  For example, you might ask patients to express the amount of pain they are feeling on a scale of 1 to 10. 3  A score of 7 means more pain that a score of 5, and that is more than a score of 3.
Also be sure a hole has not been punched in the bellows as this will cause a vacuum leak. The second thing that causes breaker to blow is simply an old worn out electric pump motor, especially in salt water applications. The third cause is that the holding tank is full and the vent line is plugged.
If an intake valve is in the open position that fuel will enter the cylinder where it will leak past the rings and eventually mixed with the engine oil. This can cause severe engine oil thinning which can lead to engine bearing damage, scorched cylinder side walls and in some cases an explosion inside the engine. There has been reported cases where leaking fuel injectors caused hydro lock because so much fuel has accumulated on top of the piston that when the engine was turned over the engine locked because it could not compress the liquid in the cylinder.