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.
New World vultures have weak talons but a strong sense of smell. They are able to locate carcasses with their sense of smell alone, but Old World vultures must rely on their excellent vision to detect carcasses. There are only 2 species of condors, the California Condor and the Andean Condor. Both species are relatives of New World vultures, but are not closely related to Old World Vultures. The 2 species of condors are larger than other New World vultures such as the Turkey Vulture and Black Vulture. None of the Old World vultures, regardless of size, is called a condor. Source(s):