Say is the average increase in shoe size for upper-class people compared to middle-class people: then the Wald test can be used to test whether is 0 (in which case social class has no association with shoe size) or non-zero (shoe size varies between social classes).
There are many different species of vultures and each has a different type of habitat. Turkey vultures are the most prominent of the New World vultures and can be found in Southern Canada, the Continental United States, Mexico, Central America and South America. These vultures live in small caves, beneath bushes, in hollowed out logs, and sometimes in abandoned structures.
Not surprisingly, many populations of turkey vultures are migratoryâheading north in spring and south in fall. That is why we almost never see turkey vultures in winter, at least in the Coachella Valley proper. In our region, the overwhelming majority of them have headed south into Mexico, Central America and, yes, Colombia. That is why Colombian fishermen see so many in winter and we donât see any.