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 are two main types of recycled plastic: PET, or #1 plastic, can be translucent or tinted, making it the clear choice for water and soft drink bottlesâthough the higher the percentage of recycled material, the more discoloration that occurs, says Marny Bielefeldt, marketing manager at St. Louis-based Alpha Packaging.