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.
Plastic marked with an SPI code of 4 is made with low-density polyethylene, or LDPE. LDPE is not commonly recycled, but it is recyclable in certain areas. It tends to be both durable and flexible. It isn't known to release harmful chemicals into objects in contact with it, making it a safe choice for food storage.
Types of Plastic Recycling These Products. The products we use can have a serious impact on the environment, which is why being able to identify a plasticâs SPI code is more important now than ever before. Luckily, most of the different types of plastic are relatively easy to recycle. Check with your local recycling service to find out what kinds of plastic are acceptable. Recycling is an important way to ensure sustainability and a green planet for future generations.