Question

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.† You would like to see if the data support this conclusion. The file HomePrices contains data on 30 existing home sales in 2006 and 40 existing home sales in 2009.

2006 ($)

213,100	226,200	239,100
214,300	161,700	181,200
228,600	222,100	228,900
235,800	219,400	238,800
301,800	264,200	320,200
315,000	118,900	172,400
137,500	212,800	175,400
311,400	296,900	292,500
287,700	246,500	195,600
155,300	152,400	211,200

2009 ($)

155,400 189,800 200,800 280,400 213,200 181,100 117,400 130,000 170,000 149,600 146,200 54,400 213,800 186,000 182,100 180,000 215,700 164,200 95,300 239,500 207,200 188,200 169,400 185,600 177,000 178,000 161,200 249,200 146,400 99,800 246,700 173,500 138,100 112,200 137,500 147,900 179,000 116,200 197,500 164,200

(a) Provide a point estimate of the difference (in dollars) between the population mean prices for the two years. (Use year 2006 − year 2009. Round your answer to the nearest dollar.)

$ ?

(b) Develop a 99% confidence interval estimate of the difference (in dollars) between the resale prices of houses in 2006 and 2009. (Use year 2006 − year 2009. Round your answers to the nearest dollar.)

$  to $

Find the value of the test statistic. (Round your answer to three decimal places.)

Find the p-value. (Round your answer to four decimal places.)

p-value =

Answer 1

Two-Sample T-Test and CI: 2006, 2009

Method

μ₁: mean of 2006

µ₂: mean of 2009

Difference: μ₁ - µ₂

Equal variances are not assumed for this analysis.

Descriptive Statistics

Sample	N	Mean	StDev	SE Mean
2006	30	225923	55252	10088
2009	40	170993	44958	7109

Estimation for Difference

Difference	99% CI for Difference
54931	(21982, 87880)

Test

Null hypothesis	H₀: μ₁ - µ₂ = 0
Alternative hypothesis	H₁: μ₁ - µ₂ ≠ 0

T-Value	DF	P-Value
4.45	54	0.0000

a) 54931

b) (21982, 87880)

c) 0.0000