U.S. Manufactured General Aviation Shipments, 1984–2016
Year			Planes			Year			Planes			Year			Planes			Year			Planes
	1984			3,003			1992			1,513			2000			3,388			2008			3,651
	1985			2,601			1993			1,536			2001			3,206			2009			2,157
	1986			2,067			1994			1,500			2002			2,779			2010			1,906
	1987			1,657			1995			1,649			2003			2,709			2011			1,895
	1988			1,784			1996			1,687			2004			2,927			2012			2,088
	1989			2,107			1997			2,121			2005			3,429			2013			2,187
	1990			1,716			1998			2,772			2006			3,719			2014			2,203
	1991			1,593			1999			3,076			2007			3,851			2015			2,164

 

 

 Click here for the Excel Data File
 

(a) Plot the data on U.S. general aviation shipments.
 

Plot A	Plot B	Plot C	Plot D

 

 

• Plot A

• Plot B

• Plot C

• Plot D

 
(b) Describe the pattern and discuss possible causes. Hint: What economic factors affect major capital investments? (You may select more than one answer. Click the box with a check mark for the correct answer and double click to empty the box for the wrong answer.)
 
The factors affecting major capital investments:
  

• Business cyclesunanswered
• Interest ratesunanswered
• Foreign demandunanswered
• Forecastingunanswered

(c) Would a fitted trend be helpful? Explain.
 
 (Click to select)  Yes  No  , there is  (Click to select)  clear  no clear  trend over the past 30 years.
 
(d) Fit a moving average (e.g., period 2) to the data. Is it useful?
 
 (Click to select)  Yes  No  , a two year or three year moving average would be an  (Click to select)  acceptable  unacceptable  forecasting method for this time series.
 
(e) Make a forecast for 2016 using a method of your choice (including a judgment forecast). Justify your method. (Round your answer to the nearest whole number.)