The experimental units are what you apply the treatments to. In this experiment it would be the subjects or the customers in this situation since they will be treatment (either standing at their regular height or squatting to meet the eye level which could affect the amount of tip they give). An example of randomization can be numbering each table in the restaurant and picking them out of a hat and going to that table that you randomly chose and imposing the treatment on the customers there. Because tips depend on the income of the customers and how much they are willing to give for their meal. If not even income some people are willing to give despite how much money they make so their tips may higher than the wealthy crowd. Other factors the experimenters may not be able to control is the mood of the customers as well isn't it more likely if someone is enjoying their time to give more to the server despite the service the waiter.
Answer:
A market for cats would have had a positive externality.
Because the cats would kill the rats on sight since that is their natural behavior.
However, it is interesting to mention, that the cat's killing has been more of a "mythic" aspect of this story, since it fails to take into account that since the black death was caused by the<em> yersinia pestis</em> bacteria, cats could have been also infected, and since their interactions with humans are greater than rats or fleas, the real outcome could have been totally unexpected.
They had strong ties with Britain.
Booker T. Washington and W.E.B. DuBois were two important leaders of the Black community in the United States. However, they each had very different opinions about the role of the African community, and on how equality could be achieved.
Booker T. Washington believed that the Black community needed to adopt a philosophy of self-help, racial solidarity and accomodation. He believed that African Americans had the duty to educate themselves and improve their livelihood in order to be taken seriously by white Americans. On the other hand, W.E.B. DuBois believed that this approach only put an extra burden on black people, while ignoring the responsibilities of whites. He argued that social change had to come through political change, and advocated political action.
I believe that their differences were as substantial as the friction between their followers. The two men had very different opinions about race and advancement. Moreover, I believe that the opinions of Booker T. Washington were more suited to the temper of the times as he took a more positive view of white people and a more negative view of conflict and political activism.
