DQ1 Week 3 Please respond to this discussion question by Thursday Day 3 Why are graphs and charts used to represent information What distinguishes a histogram from a bar chart What are some examples of grouped and ungrouped data What would be the most appropriate graphical representation to show the dispersion of new home prices in a particular area Why Data on its face can be hard to discern nuances of underlying data When placed in a graph the data comes alive so to speak generating a graphic story of the explicit data x Y x2 says very little to the reader unfamiliar with math notation however a graph of real numbers for x illustrates a wine glass look that becomes familiar In data graphing for business the simple graphs show empirically what the data desires to say such as in data of revenues over a five year period If it is rising and it is graphed not only can the story be told in a meaningful way but a sense of future growth can be inferred and that story shown to a global audience with meaning A bar chart is simply data relating to some variable say monthly insurance expenses A histogram is the graph of some distribution of data in a variable Say population of people in a shopping mall by the hour over a four hour peak period The distribution will have a mean and a variance that can be calculated where a variance of one is 67 of the distribution of people in a peak hour Some data are skewed in one direction and some data have outliers that do not fit well and can be ignored if a relevant argument can be made Grouped data are the normal distribution of elements in a variable Ungrouped data are problematic data that are in the distribution but are outliers so extreme they do not fit within the normal boundaries of a bell curve To define new home prices in an area a plot using circles of differing size as a histogram depiction on a map is used where the larger the size the higher the prices of new homes Graphing on a map creates meaning to a broad audience and the histogram of the dot plot sizing creates area specific data that underlies the map of an area For new homeowners this map creates a key of where to look Add in data of crime statistics data on urban blight index and an index of amenities such as walk ability to shopping and food creates a very meaningful map The histogram is a powerful method of showing frequency distributions when coupled with maps can be quite a powerful message to a general audience