Question

The National Association of Home Builders provided data on the cost of the most popular home remodeling projects. Sample data on cost in thousands of dollars for two types of remodeling projects are as follows.

Kitchen	Master Bedroom
25.2	18.0
17.4	22.9
22.8	26.4
21.9	24.8
19.7	26.9
23.0	17.8
19.7	24.6
16.9	21.0
21.8
23.6

Develop a point estimate of the difference between the population mean remodeling costs for the two types of projects.

Develop a 90% confidence interval for the difference between the two population means.

Home values tend to increase over time under normal conditions, but the recession of 2008 and 2009 has reportedly caused the sales price of existing homes to fall nationwide (Businessweek, March 9, 2009). You would like to see if the data support this conclusion. The chart below HomePrices contains data on 30 existing home sales in 2006 and 40 existing home sales in 2009.

Provide a point estimate of the difference between the population mean prices for the two years.

Develop a 99% confidence interval estimate of the difference between the resale prices of houses in 2006 and 2009.

Would you feel justified in concluding that resale prices of existing homes have declined from 2006 to 2009? Why or why not?

2006 ($1000s)	2009 ($1000s)
213100	155400
226200	189800
239100	200800
214300	280400
161700	213200
181200	181100
228600	117400
222100	130000
228900	170000
235800	149600
219400	146200
238800	54400
301800	213800
264200	186000
320200	182100
315000	180000
118900	215700
172400	164200
137500	95300
212800	239500
175400	207200
311400	188200
296900	169400
292500	185600
287700	177000
246500	178000
195600	161200
155300	249200
152400	146400
211200	99800
	246700
	173500
	138100
	112200
	137500
	147900
	179000
	116200
	197500
	164200

Answer 1

By using the given data we have to find out the sample meansand sample standard deviations