Christy King MA 331 – Final Project [Part II - Report] November 30th 2008 General Objective: To determine the significance in vendor selection when purchasing Fantasy books online. Vendors Being Observed: All data has been taken from the vendor’s websites: www.bn.com www.amazon.comwww.borders.com Specific Objectives / Key Questions & Answers: • Does there appear to be a significant difference in the prices of books between the three selected venders (Barns & Nobel, Amazon & Borders)? No: There does not appear to be a significant difference in the prices of books between the three venders based on the studies which follow. While there is a difference between the prices for most of the individual books studied, there is not strong proof statistically for variance between the venders. This holds true for an analysis which includes the factor of Publication Year. My beset advice to an individual buying books online would be to compare the prices between the three sites at the time of purchase, as the statistical analysis has shown no clear cut differences between the vendors. Based strictly on the means one could safely choose to buy from Amazon in a rush, but it is wise to simply take the time to check each website.Christy King MA 331 – Final Project [Part II - Report] November 30th 2008 a. Whose books are the overall cheapest, highest, etc? One of the most significant results found was through a simple summary of each data set. By looking at the means for each vender and the average of all vender prices we find that Barnes and Nobel has a mean price relatively the same as the overall average price, Amazon has a mean slightly lower than the overall average and Borders a slightly higher mean. The below graph depicts the distribution of the prices. Note that Red = Barnes & Nobel, Blue = Amazon, Green = Borders. It is somewhat clear from the graph that the means would be distributed as discussed above. [For non-superimposed graphs, see the Other graphs section]Christy King MA 331 – Final Project [Part II - Report] November 30th 2008 The histograms which follow show us that there is relatively little difference in the prices between the three venders. Though the differences in means do exist, they are not extreme.Christy King MA 331 – Final Project [Part II - Report] November 30th 2008 It is important to note that the histogram of all of the prices appears similar if not the same as the histograms of the three vendors, this is another good indication that the vendors are following the same pricing scheme. Furthure AnalysisChristy King MA 331 – Final Project [Part II - Report] November 30th 2008 The Below Stem Plots show a similar indication that there is no stark difference in the data received for each vendor.Christy King MA 331 – Final Project [Part II - Report] November 30th 2008 This is a stem plot just to give a clear view of all of the prices that have been collected. Summary Statistics – to give a clear representation of the means that we are dealing with as well as sum, var & n Summary information for whole data set.Christy King MA 331 – Final Project [Part II - Report] November 30th 2008 Analysis of Variance: The analysis of variance for the vendors as shown below proved insignificant, indicating a clear lack of difference between the prices obtained from each vendor. The “Confidence Interval on Pooled Variance” Is fairly massive this indicates that there is a low likelihood of variance. Note: The below summary of “fit” shows that the vendors have no effect on each other.Christy King MA 331 – Final Project [Part II - Report] November 30th 2008 A Boxplot further helps us to visualize the spread of the data among the three vendors. It is clear that the three vendor’s behaviors are very similar. Their means are nearly equivalent as was seen in the previous analysis. It appears that Barnes & Nobel has more books it the mid range of $75-100.Christy King MA 331 – Final Project [Part II - Report] November 30th 2008 Does publication date have a significant effect on the differences in the prices of books among the three vendors in this study? From the initial general plot of Publication_Year vs. each Vender, we might pre-assume that there will be little to no significance in publication year. The below graph shows the prices of books vs. their publication year. Again, Red = Barnes & Nobel, Blue = Amazon, Green = Borders. Note: there appears to be an indication that prices are generally higher in recent years and that moderately older books around the time of 1980 are also a bit pricier. [For non-superimposed graphs, see the Other graphs section]Christy King MA 331 – Final Project [Part II - Report] November 30th 2008 By classifying each book as either Old, Moderately Old or New the below Boxplot was created to give a visualization of the data. It is obvious that there is very little overall change in the price of books based on age. • Does the price range of the book have an effect on variance in price between vendors? (Or in other words, is there more variance between vendors for books in the range of $10, $20, $100, etc.) a. No, Given that the price histogram followed the individual histograms of each vendor it is easy to see that there is also insignificant difference based on price range.Christy King MA 331 – Final Project [Part II - Report] November 30th 2008 Methods Which Were Used: • General data analysis & comparisons • Histograms • Stem plots • Scatter Plots • Boxplots • Analysis of both categorical and quantitative variables • Regression Analysis • One-Way ANOVA test • T-tests Data Set: Table v1: Title Barnes_Nobel _Price Amazon_ Price Borders_ Price Publication_ Year Classification Average_ Price_in_Range Average_Price_in_Range_ Rounded Acacia Audio 119.99 87.59 119.99 2007 New 103.79 110 All the Weyers of Pern 101.8 92.89 127.25 2008 New 97.345 110 Artemis Fowl: The Time Paradox 12.59 12.23 12.59 2008 New 12.41 20 Beguilement Audio 90 90 90 2007 New 90 90 Bitten 7.99 7.99 7.99 2004 Moderatly Old 7.99 10 book of Reality, The 4.99 4.99 4.99 2006 Moderatly Old 4.99 10 Canterville Ghost, The 3.55 5.95 5.95 1970 Old 4.75 10 Confessor 23.96 19.77 29.95 2007 New 21.865 30 Confusion, The 200 200 200 2005 Moderatly Old 200 200 Corduroy 12.23