Questions and Answers

Which forecasting technique can place the most emphasis on recent values? How does it do this?

QUESTION: “Which forecasting technique can place the most emphasis on recent values? How does it do this?” [signinlocker] ANSWER: Exponential smoothing weighs all previous values with a set of weights that decline exponentially. It can place full weight on the most recent period (with an alpha of 1.0). This, in effect, is the na├»ve approach, …

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What is the result of an attempt to add, subtract, multiply, or divide two number fields, one of which

QUESTION: What is the result of an attempt to add, subtract, multiply, or divide two number fields, one of which contains a null value? [signinlocker] ANSWER: The Inclusion of a null value results in each of these computations yielding a null value as the result. [/signinlocker]

Which comparison operators can be used when searching for null values? Which comparison operators

QUESTION: Which comparison operators can be used when searching for null values? Which comparison operators cannot be used when searching for null values? What is the result when these unacceptable comparison operators are used when searching for null values? [signinlocker] ANSWER: None of the comparison operators except for IS NULL or IS NOT NULL can …

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What is the difference between a character field that contains a null value and a character field that

QUESTION: What is the difference between a character field that contains a null value and a character field that contains a single blank space? [signinlocker] ANSWER: A character field that contains a null value is zero characters long, while a character field that contains a single blank space has a length of one character. [/signinlocker]