The range rule tells us that the standard deviation of a sample is approximately equal to one fourth of the range of the data. In other words s = (Maximum â Minimum)/4. This is a very straightforward formula to use, and should only be used as a very rough estimate of the standard deviation.
Often abbreviated as âDMEâ, durable medical equipment includes various types of walking aids, transfer equipment, bath safety and wheelchairs. As the name implies, this category must be manufactured and tested to be âdurableâ because patients who use this equipment rely on it to keep them safe and comfort.
Types of items that are considered to be durable medical equipment include air fluidized beds, canes, commode chairs and crutches. It also includes infusion pumps and some of the medicines used in them. Patient lifts, suction pumps and traction equipment is also considered to be durable medical equipment.