Worksheet "Mattel" in "Assignment 5.x/sx" contains total quarterly revenues for Mattel, Inc. (the famous American toy manufacturer) between 2005 and 2012. a) Develop a multiple regression model that combines seasonal effects and a trend component for these data. Carefully describe how you build this model and how you would interpret the slopes of the independent variables. b) Based on your model from part a), what revenues would you predict for the second and the fourth quarter of 2013 , respectively? \begin{tabular}{|r|r|r|} \hline Year & Quarter & Revenues \\ \hline 2005 & 1 & 783.12 \\ \hline 2005 & 2 & 886.823 \\ \hline 2005 & 3 & 1666.145 \\ \hline 2005 & 4 & 1842.928 \\ \hline 2006 & 1 & 793.347 \\ \hline 2006 & 2 & 957.655 \\ \hline 2006 & 3 & 1790.312 \\ \hline 2007 & 4 & 2108.842 \\ \hline 2007 & 1 & 940.265 \\ \hline 2007 & 2 & 1019.625 \\ \hline 2007 & 3 & 1857.574 \\ \hline 2008 & 4 & 2201.526 \\ \hline 2008 & 2 & 919.299 \\ \hline 2008 & 3 & 1112.431 \\ \hline 2008 & 4 & 1939.957 \\ \hline 2009 & 1 & 785.646 \\ \hline 2009 & 2 & 898.197 \\ \hline 2009 & 3 & 1791.875 \\ \hline 2009 & 4 & 1955.128 \\ \hline 2010 & 1 & 880.082 \\ \hline 2010 & 2 & 1018.503 \\ \hline 2010 & 3 & 1833.056 \\ \hline 2010 & 4 & 2124.554 \\ \hline 2011 & 1 & 951.856 \\ \hline 2011 & 2 & 1161.667 \\ \hline 2011 & 3 & 1998.76 \\ \hline 2011 & 4 & 2153.754 \\ \hline 2012 & 1 & 928.449 \\ \hline 2012 & 2 & 1158.711 \\ \hline 2012 & 3 & 2077.816 \\ \hline 2012 & 4 & 2255.905 \\ \hline \end{tabular}