A real estate agent compares the selling prices of randomly
A real estate agent compares the selling prices of randomly selected homes in two municipalities in southwestern Pennsylvania to see if there is a difference. The results of the study are shown. Is there enough evidence to reject the claim that the average cost of a home in both locations is the same? Use a=0.01. Scott: Xbar = 93,430, standard deviation = 5602, n= 35. Ligioner: Xbar= 98043, standard deviation= 4731, n=40.
Solution
Let mu1 be the mean for Scott
Let mu2 be the mean for Ligioner
The test hypothesis:
Ho: mu1=mu2 (i.e. null hypothesis)
Ha: mu1 not equal to mu2 (i.e. alternative hypothesis)
The test statistic is
Z=(xbar1-xbar2)/sqrt(s1^2/n1+s2^2/n2)
=(93430-98043)/sqrt(5602^2/35+4731^2/40)
=-3.82
It is a two-tailed test.
Given a=0.01, the critical values are Z(0.005) = -2.58 or 2.58 (from standard normal table)
The rejection regions are if Z<-2.58 or Z>2.58, we reject the null hypothesis.
Since Z=-3.82 is less than -2.58, we reject the null hypothesis.
So we can conclude that there is enough evidence to reject the claim that the average cost of a home in both locations is the same
