Quantitative and Qualitative Forecasting

7 l-ott r,r: r.s rt tl chupter I I 459 Computing a Seasonal Factor from thc Actual Data and Trend l,inc e)frceI Fo the Excl tffiplate, visit -mhhe.@m4@bs14e. 700 300 Qu.*ren I II F_- 201 1 IiI FtoM T[sNn AcruaL Eeue'rroN Arrrorntt FIT : 176.i + 52.31 R.qtro or' ACTUAL _ TREND 20t2-----------sr SBnsoN,u- Facror (Avsnact or S.q.Mn Qulnrens n Bor:sYrans) 2411 I lt lil IV 2012 I II ilt IV 300 2A0 220 530 520 420 400 700 280.6 332.9 385.1 /aa I 48S.6qt1 a 594.2 1.19 0 I 1.25 110.79 ilt 0.70 iv 1.28 0.74 1.18 (2) Deseasonalized Demand (1) Psntoo(/) QUARTER (3) ACTLTALI)rrralNo(y) (4) AVERAGE op rnr S,tttE QUARTERS OF EACH YEAR (s) (6) DESEASONALiZED Sr.rsoN.a.r Dr.u.rNo (y',r) l- ( l uk Col . (1 , + CuL. (51 (7) (8) TXlt 1: CoL. (l ) x (CoL. ll' C0L. (6) 1 I 600 (600 + 2,400 + 3,800)/3 . = ?,266.r 2 ll 1,550 (.1 ,550 + 3,100 + 4,500)/3 : 3.050 lll 1,500 (1,500 + 2,600 + 4 000)13 0.97 : 2,740 4 tv 1 ,s00 (1,500 + 2,900 + 4 900)/3 1.12 : 3,1 00 0.82 1.10 0.82 1.10 0.97 1.12 0.82 1.10 0.97 1ZO3 735.7 1,412.4 1,544.0 1,344.8 2,942.4) R)47 2,676.22AOOO 4,659.2 4,100.4 +, lt/.J/?o)o 333"r0J. /J3./ 2,824.7 4,631.9 5,379.0 14,713.2 16,948.4 18,733.6 20,798.9 41,932.7 41 ,004.145,290.1 52,114.5 265.706.9 16 5l 6 ll 7 llt 8tv 9l 10 ll 11 lll 12 IV 7B 2 4AO 3,100 2,600 2,900 3,800 4,500 4,000 4,900 33,350. s_ ; 78 _ ^ , ^ Ztyo- nry" t65.706.9 - t?r6.5)2.779.2 _ .4' ) r - = o.r " .i _ ---- 659 _ij(. o+z.z 1t Ya:3335A/p:2]792 a: t:- bt - 2.719.2 - 342.2(6.5): 554.9 Thereforc, Y - a i bl- 554,9 1 342.2t 3649 64 B1 100 121 144 650 .Column 3 and column 6 totals should be equal at 33,350. Differences are due to rounding. Column 5 was rounded to two decimal places. exhibit 18.10 400 _s00 200 100