What is the difference between a specialization hierarchy and a specialization lattice?

QUESTION: How are null values treated when one or more appears during the execution of a group function?

QUESTION: The city government has collected the following data on annual sales tax collections and new car registrations: Determine the following: (a) The least-squares regression equation. (b) Using the results of part (a), find the estimated sales tax collections if …

QUESTION: The following are two weekly forecasts made by two different methods for the number of gallons of gasoline, in thousands, demanded at a local gasoline station. Also shown are actual demand levels, in thousands of gallons: What are the …