TABLE 16-13 Given Below Is the Monthly Time-Series Data for U.S. Retail

question 156

Short Answer

TABLE 16-13
Given below is the monthly time-series data for U.S. retail sales of building materials over a specific year.

The results of the linear trend, quadratic trend, exponential trend, first-order autoregressive, second-order autoregressive and third-order autoregressive model are presented below in which the coded month for the first month is 0:




-Referring to Table 16-13, what is the exponentially smoothed forecast for the 13ᵗʰ month using a smoothing coefficient of W = 0.25 if the exponentially smooth value for the 10ᵗʰ and 11ᵗʰ month are 9,477.7776 and 9,411.8332, respectively?

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Definitions:

True Correlation

The actual degree of a linear relationship between two variables, excluding any error or distortion.

Linear Relationship

A type of correlation where there is a constant change rate between two variables, indicative of a straight line when graphed.

Confidence Interval Estimate

A range of values, derived from sample statistics, that is likely to contain the value of an unknown population parameter.

Prediction Interval

A prediction of the range within which future data points are likely to land, based on past observations, along with a specified level of confidence.