A box and whisker plot is a graphical method of displaying variation in a set of data. In most cases a histogram provides a sufficient display; however, a box and whisker plot can provide additional detail while allowing multiple sets of data to be displayed in the same graph. Some types are called box and whisker plots with outliers.
Can you compost Leylandii branches and hedge clippings - Yes. We were quite surprised to learn some experienced composters advise not to add Leyandii cuttings as they are apparently too acidic. Composting bacteria can remain active in all but the most acidic conditions.
Sawdust that is created from cutting natural wood is safe for your compost no matter what kind of tree the wood comes from. Just make sure the wood has not been treated with any chemicals. Another option with sawdust is to try mixing it in with potting soil.