# Aj Davis Department Stores

1219 WordsAug 3, 20135 Pages
AJ Davis Department Stores - Project Part A, B, and C Stacie Borowicz June 14, 2013 Math 533 Project Part A – Exploratory Data Analysis Credit Balance (\$) Based on a sample of 50 customers, the credit balance for customers of Davis Department stores is on average \$3970.00. Based on the graph, 18 of the 50 sampled fall below and 17 fell above the average. The standard deviation for credit balance is 931.9. Income Annual Income of Davis Department Stores customers range anywhere from \$22,000 to \$67,000. Majority of their customers have an annual income of about \$43,740. The standard deviation for income is \$14,640. Size Average household size is about 3.4. Based on the graph above, 15 of the 50 sampled have a…show more content…
10. For a household size of 10 the confidence interval is (5926.96, 7320.36) which will include the mean credit balance and the prediction interval is (5195.30, 8052.01) which will include the actual credit balance for a household of that size. 11. Regression Equation Credit Balance(\$) = 1276.02 + 32.2719 Income (\$1000) + 346.852 Size + 7.88209 Years (Appendix C) APPENDIX A General Regression Analysis: Credit Balance(\$) versus Size Regression Equation Credit Balance(\$) = 2591.44 + 403.221 Size Coefficients Term Coef SE Coef T P Constant 2591.44 195.064 13.2851 0.000 Size 403.22 50.946 7.9147 0.000 Summary of Model S = 620.162 R-Sq = 56.62% R-Sq(adj) = 55.71% PRESS = 19992921 R-Sq(pred) = 53.02% Analysis of Variance Source DF Seq SS Adj SS Adj MS F P Regression 1 24092210 24092210 24092210 62.6421 0.000000 Size 1 24092210 24092210 24092210 62.6421 0.000000 Error 48 18460853 18460853 384601 Lack-of-Fit 5 2499467 2499467 499893 1.3467 0.263274 Pure Error 43 15961386 15961386 371195 Total 49 42553062 Fits and Diagnostics for Unusual Observations Credit Obs Balance(\$) Fit SE Fit Residual St Resid 5 1864 3397.89 113.691 -1533.89 -2.51600 R R denotes an observation with a large standardized residual. APPENDIX B