Practical Applications of Data Mining

152 Chapter 4 StatiStiCS for Data Mining

SQL 6 retrieves the Z value 2.0, which means that the data values do not

strongly reject the null hypothesis with a probability of 97.5%. Since the value

is not much more than 1.96, we do not reject the null hypothesis that there is

no difference in sale prices between corner-located and non–corner-located

houses. We do not have sufficient evidence to conclude that the null hypoth-

esis is wrong, and we are not in favor of the alternative hypothesis. Therefore,

the prices for the corner-located houses and the prices for the non–corner-

located houses are not considered different.

4.5 correlatIon coeffIcIent ...