Mean. The mean of an observation variable is a numerical measure of the central location of the data values. It is the sum of its data values divided by data count. Hence, for a data sample of size n, its sample mean is defined as follows:Similarly, for a data population of size N, the population mean is:ean. The mean of an observation variable is a numerical measure of the central location of the data values. It is the sum of its data values divided by data count. Hence, for a data sample of size n, its sample mean is defined as follows:
Names of territorial origin were common, a man would have had the surname Langford if he was from the village of Langford. An example of this is Osm' de Langeford who was recorded in the Pipe Rolls for Wiltshire in 1130. The name Osm' de Langeford means Osm' from the village of Langford.
There are a number of places in England named with this word, as for example Lund in Lancashire, East Yorkshire, and North Yorkshire, Lunt in Merseyside, and Lound in Lincolnshire, Nottinghamshire, and Suffolk, and the surname may derive from any of these.