l Seasonal indexes A seasonal index is a factor that adjusts a trend value to compensate for typical seasonal fluctuation in that period of a seasonal cvcle a seasonal index is expressed as a percentage with a value of 100% corresponding to an average position in a seasonal cycle o 2002 The Wadsworth Group
Seasonal Indexes • A seasonal index is a factor that adjusts a trend value to compensate for typical seasonal fluctuation in that period of a seasonal cycle. • A seasonal index is expressed as a percentage with a value of 100% corresponding to an average position in a seasonal cycle. © 2002 The Wadsworth Group
I Seasonal indexes- An example eason ex Annual Quarter) Value 84.5 102.3 95.5 117.7 If the trend value for Quarter I in the given year was 902, the value with seasonal fluctuation would be y=T·S=902·84.5%=7622 o 2002 The Wadsworth Group
Seasonal Indexes - An Example Season Index (Annual Quarter) Value I 84.5 II 102.3 III 95.5 IV 117.7 • If the trend value for Quarter I in the given year was 902, the value with seasonal fluctuation would be y = T • S = 902 • 84.5% = 762.2 © 2002 The Wadsworth Group