Question about Interval Estimation
Gulf Real Estate Properties, Inc., is a real estate firm located in southwestern Florida. The company, which advertises itself as “expert in the real estate market,” monitors condominium sales by collecting data on location, list price, sale price, and number of days it takes to sell each unit. Each condominium is classified as Gulf View if it is located directly on the Gulf of Mexico or No Gulf View if it is located on the bay or a golf course, near but not on the Gulf. Sample data from the Multiple Listing Service in Naples, Florida, provided recent sales data for 40 Gulf View condominiums and 18 No Gulf View condominiums.* Prices are in thousands of dollars. The data are shown in SPSS file Question 1 Gulf .
(a) Use appropriate descriptive statistics to summarize each of the three variables for the 40 Gulf View condominiums (mean, standard deviation, and variance).
(b) Use appropriate descriptive statistics to summarize each of the three variables for the 18 No Gulf View condominiums (mean, standard deviation, and variance).
(c) Compare your summary results. Discuss any specific statistical results that would help a real estate agent understand the condominium market.
(d) Develop a 95% confidence interval estimate of the population mean sales price and population mean number of days to sell for Gulf View condominiums. Interpret your results.
(e) Develop a 95% confidence interval estimate of the population mean sales price and population mean number of days to sell for No Gulf View condominiums. Interpret your results.
(f) Assume the branch manager requested estimates of the mean selling price of Gulf View condominiums with a margin of error of $40,000 and the mean selling price of No Gulf View condominiums with a margin of error of $15,000. Using 95% confidence, how large should the sample sizes be?
(g) Gulf Real Estate Properties just signed contracts for two new listings: a Gulf View condominium with a list price of $589,000 and a No Gulf View condominium with a list price of $285,000. What is your estimate of the final selling price and number of days required to sell each of these units?
and hers is the data I have received
Gulf View Condominiums No Gulf View Condominiums
List Price Sale Price Days to Sell List Price Sale Price Days to Sell
495.0 475.0 130 217.0 217.0 182
379.0 350.0 71 148.0 135.5 338
529.0 519.0 85 186.5 179.0 122
552.5 534.5 95 239.0 230.0 150
334.9 334.9 119 279.0 267.5 169
550.0 505.0 92 215.0 214.0 58
169.9 165.0 197 279.0 259.0 110
210.0 210.0 56 179.9 176.5 130
975.0 945.0 73 149.9 144.9 149
314.0 314.0 126 235.0 230.0 114
315.0 305.0 88 199.8 192.0 120
885.0 800.0 282 210.0 195.0 61
975.0 975.0 100 226.0 212.0 146
469.0 445.0 56 149.9 146.5 137
329.0 305.0 49 160.0 160.0 281
365.0 330.0 48 322.0 292.5 63
332.0 312.0 88 187.5 179.0 48
520.0 495.0 161 247.0 227.0 52
425.0 405.0 149
675.0 669.0 142
409.0 400.0 28
649.0 649.0 29
319.0 305.0 140
425.0 410.0 85
359.0 340.0 107
469.0 449.0 72
895.0 875.0 129
439.0 430.0 160
435.0 400.0 206
235.0 227.0 91
638.0 618.0 100
629.0 600.0 97
329.0 309.0 114
595.0 555.0 45
339.0 315.0 150
215.0 200.0 48
395.0 375.0 135
449.0 425.0 53
499.0 465.0 86
439.0 428.5 158