When the Underlying Mean of a Time Series Is Very

question 139

Multiple Choice

When the underlying mean of a time series is very stable and there are no trend, cyclical, or seasonal influences,

• A) a simple moving average forecast with n = 20 should perform about the same as a simple moving average forecast with n = 3.
• B) a simple moving average forecast with n = 20 should outperform a simple moving average forecast with n = 3.
• C) a simple moving average forecast with n = 3 should outperform a simple moving average forecast with n = 20.
• D) an exponential smoothing forecast with alpha = 0.30 should outperform a exponential smoothing forecast with alpha = 0.01.

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Definitions:

Confidence Interval

A selection of numerical values, culled from sample data, likely to hold within it the value of an unrevealed population parameter.

Population Mean

The average of all the data points in a population, representing the central tendency of the entire population's values.

Sample Mean

The average value of a set of data points taken from a sample of a larger population.

Population Parameter

A numerical value that represents a characteristic or feature of an entire population.