Informally, each tuple in a relation should represent one entity or relationship instance.

a. Attributes of different entities should not be mixed in the same relation.
b. Only foreign keys should be used to refer to other entities.
c. Entity and relationship attributes should be kept apart as much as possible.

How is the division of labor accomplished?

Companies in the u.s. car rental market vary greatly in terms of the size of the fleet, the number of locations, and annual revenue. in 2011 hertz had 320,000 cars in service and annual revenue of approximately $4.2 billion. the following data show the number of cars in service (1000s) and the annual revenue ($ millions) for six smaller car rental companies (auto rental news website, august 7, 2012). excel file: data14-09.xls if required, enter negative values as negative numbers. a. select a scatter diagram with the number of cars in service as the independent variable. b. what does the scatter diagram developed in part (a) indicate about the relationship between the two variables? c. use the least squares method to develop the estimated regression equation (to 3 decimals). ŷ = + x d. for every additional car placed in service, estimate how much annual revenue will change. by $ e. fox rent a car has 11,000 cars in service. use the estimated regression equation developed in part (c) to predict annual revenue for fox rent a car. round your answer to nearest whole value. $ million hide feedback partially correct

T-comm makes a variety of products. it is organized in two divisions, north and south. the managers for each division are paid, in part, based on the financial performance of their divisions. the south division normally sells to outside customers but, on occasion, also sells to the north division. when it does, corporate policy states that the price must be cost plus 20 percent to ensure a "fair" return to the selling division. south received an order from north for 300 units. south's planned output for the year had been 1,200 units before north's order. south's capacity is 1,500 units per year. the costs for producing those 1,200 units follow