Estimate trend using 4 yearly centered moving averages :
Year
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
Population (in tonnes)
78
73
71
73
75
78
73
77
70
69
Answers
Answer:
Explanation:
calculate the trend using 4 yearly centered moving averages :
population: 78 73 71 73 75 78 73 77 70 69
Computation of Trend values ( 4 years Moving Averages)
year population Total of 4 years 4 years M.A
2000 78
2001 73
2002 71
2003 73 304 76
2004 75 292 73
2005 78 297 74.25
2006 73 299 74.75
2007 77 303 75.75
2008 70 298 74.50
2009 69 289 72.25
step 1: 78+ 73 + 71+ 73 = 304 /4 = 76
step 2: 73 + 71+ 73 + 75 = 292 /4 = 73
step 3: 71+ 73 + 75 + 78 = 297 /4 = 74.25
step 4: 73 + 75 + 78 + 73 = 299 /4 = 74.75
step 5: 75 + 78 + 73 + 77 = 303 /4 = 75.75
step 6: 78 + 73 + 77 + 70 = 298 /4 = 74.50
step 7: 73 + 77 + 70 + 69 = 289/4 = 72.25