Question

Sale Price	List Price	Days to Sell	Gulf View
475	495	130	1
350	379	71	1
519	529	85	1
534.5	552.5	95	1
334.9	334.9	119	1
505	550	92	1
165	169.9	197	1
210	210	56	1
945	975	73	1
314	314	126	1
305	315	88	1
800	885	282	1
975	975	100	1
445	469	56	1
305	329	49	1
330	365	48	1
312	332	88	1
495	520	161	1
405	425	149	1
669	675	142	1
400	409	28	1
649	649	29	1
305	319	140	1
410	425	85	1
340	359	107	1
449	469	72	1
875	895	129	1
430	439	160	1
400	435	206	1
227	235	91	1
618	638	100	1
600	629	97	1
309	329	114	1
555	595	45	1
315	339	150	1
200	215	48	1
375	395	135	1
425	449	53	1
465	499	86	1
428.5	439	158	1
217	217	182	0
135.5	148	338	0
179	186.5	122	0
230	239	150	0
267.5	279	169	0
214	215	58	0
259	279	110	0
176.5	179.9	130	0
144.9	149.9	149	0
230	235	114	0
192	199.8	120	0
195	210	61	0
212	226	146	0
146.5	149.9	137	0
160	160	281	0
292.5	322	63	0
179	187.5	48	0
227	247	52	0

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? Using 99.9% confidence, how large should the sample sizes be? (Gulf View condos are denoted by “1” in the Gulf View column, whereas No Gulf View condos are denoted by “0”. Prices are in thousands of dollars.)

Answer 1

standard deviation calculaton for sale price of gulf view condominius

values in thousand

so standard deviation =192517.8

here for 95% CI,alpha=0.05for 99.9%CI,alpha =0.1

now for,

no gulf view sale price,

we we will calculate std dev,

standard deviation=43891.7

for 95%CI

for 99.9 CI