Time series plot

Home sales are often considered an important determinant of the future health of the economy. Thus, there is widespread interest in being able to forecast total houses sold (THS). Quarterly data for THS are shown in the following table in thousands of units:


Don't use plagiarized sources. Get Your Custom Essay on
Need an answer from similar question? You have just landed to the most confidential, trustful essay writing service to order the paper from.
Just from $11/Page
Order Now







a. Prepare a time-series plot of THS. Describe what you see in this plot in terms of trend and seasonality.


b. Calculate and plot the first twelve autocorrelation coefficients for PHS. What does this autocorrelation structure suggest about the trend?


c. De-trend the data by calculating first differences: DTHSt  THSt  THSt1 Calculate and plot the first eight autocorrelation coefficients for DTHS. Is there a trend in DTHS?