Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Week 2, DQ 1, Due: Thursday Do all data have a mean, median, or mode? Explain why or why not. When is the mean the best measure of central tendency? When is the median the best measure of central tendency? What is the difference between the standard deviation and the variance? In other words, do they provide different information or serve different purposes? Feel free to add examples to meet the word requirement. Whereas data has a mean as well as a median, it doesn't always automatically contain a mode. In case a set of data doesn't have any repeating values, in that case it won't contain a mode. For a mode to exist in a data set any particular value should appear more than once in the set, therefore in case you have a data group of (50%, 68%, 75%, 97%) there will be no mode since no value appears more than once. The mean as well as median can invariably be computed for a set of data. To compute the mean one should add up all the figures in a data set and divide that value by the total quantity of figures which exist in the set. The median in a data set is the central value after sorting the data set in sequence from minimum to maximum. When computing central tendency the mean is best utilized when there are no extreme values in the data set. In case extreme values are present it may influence the mean and possibly pull the mean lower or enhance the mean giving an unreliable answer. Median, however, is helpful in computing central tendency when big extreme values are present in the data set.