These values have mean of 17 and standard deviation of about 4.1. If instead we first calculate the range of our data as 25 â 12 = 13, and then divide this number by four we have our estimate of the standard deviation as 13/4 = 3.25.
Thermoset plastics are types of plastics that retain the shapes that they are molded into. In other words, these are hard plastics. They are very durable and most of the time can be used and reused many times. These are the types of plastics that are used in aircraft parts, tires, and many others. The other half of the main types of plastics is thermoplastic.
There exist various types of hard plastics. In the waste phase, all of these types are brought together and a mixed plastics stream is generated. Mostly, such a mixed plastics stream is being sorted out on the basis of density. The recycling process has been designed in such a way that the most common plastics types such as PP, PE, PS and ABS are separated out.