Question 2 (23 Marks) The following data contains sales data on business shirts in a sample of department stores. The variables collected are described below. Sales Unit sales (in thousands) at the store Average price charged by local competitor for one business CompPrice shirt (dollars) Income Community income level (in thousands of dollars) Advertising Local advertising budget for store (in thousands of dollars) Population Population size in geographic region of store (in thousands] Price Average price charged by store for one business shirt (dollars) Urban Yes or No depending on whether store is an urban or rural location Estimate the 95% confidence interval for the population average price charged by store for one business shirt (Price) and interpret your result. (6 Marks) How large a sample should be taken to reduce the confidence interval in part (a) to $8 with the same confidence level? (6 Marks) C. Estimate a 90% confidence interval for the population proportion of urban stores. You must verify any assumptions and present your final answer in a sentence. (6 Marks) d. What is the minimum sample size required to make the confidence interval in part (c)have a quarter of its width with the same confidence level? |Sales CompPrice Income Advertising Population Price Urban Store 1 9.5 120 73 11 276 120 Yes Store 2 11.22 98 45 260 83 Yes Store 10.06 108 35 269 80 Yes Store 7.4 112 100 456 97 Yes Store S 4.15 136 64 128 Yes Store 6 10.81 119 113 72 No Store 7 6.63 110 108 Yes Store 8 11.85 131 120 Yes Store 6.54 127 Store 10 4.69 127 Store 11 11.96 112 Store 12 3.98 117 Store 13 10.96 110 Store 14 11.17 102 Store 15 8.71 144 Store 16 7.58 113 Store 17 12.29 142 Store 18 13.91 105 Store 19 8.73 124 Store 20 12.13 129 Store 21 5.08 123 Store 22 5.87 116 Store 23 10.14 140 Store 24 14.9 134 Store 25 8.39 102Sales CompPrice Income Advertising Population Price Urban Store 1 9.5 120 73 11 276 120 Yes Store 2 11.22 98 16 260 83 Yes Store 3 10.06 108 35 10 269 80 Yes Store 4 7.4 112 100 466 97 Yes Store 5 4.15 136 54 3 340 128 Yes Store 6 10.81 119 113 13 408 72 No Store 7 6.63 110 105 0 45 108 Yes Store 8 11.85 131 81 15 425 120 Yes Store 9 5.54 127 110 0 108 124 No Store 10 4.69 127 113 131 124 No Store 11 11.96 112 94 4 503 94 Yes Store 12 3.98 117 35 2 393 136 Yes Store 13 10.96 110 28 11 29 86 Yes Store 14 11.17 102 117 11 148 118 Yes Store 15 8.71 144 95 5 400 144 No Store 16 7.58 113 32 0 284 110 Yes Store 17 12.29 147 74 13 251 131 Yes Store 18 13.91 105 110 408 68 No Store 19 8.73 124 76 16 58 121 No Store 20 12.13 129 29 12 239 109 No Store 21 5.08 123 46 6 497 138 Yes Store 22 5.87 116 31 292 109 Yes Store 23 10.14 140 119 16 294 113 Yes Store 24 14.9 134 32 0 176 82 No Store 25 8.33 102 115 11 496 131 No