Mac Time Series To Find Forcast Sales

System
System Posts: 103,151 🤖 Admin 🤖
in Chat and off-topic discussion
I am having a problem with finding actual sales for the date in December 2007 paper question 1.3 (b) i have caluculated up to seasonal variation and still could get the ans publish can any one help me undersand what i have not down or what i have left out.

Thank in advance:confused1:

Comments

  • definite.studies
    definite.studies Registered Posts: 88 Regular contributor ⭐
    If you are having a problem with the trend values for the prediction, then I think it makes the problem clearer to flip the table round to show time progressing down the page instead of from left to right. i.e.

    Month Trend Variation Actual

    Dec 06 250 350 600
    Jan 07 255 (200) 55
    Feb 07 260 (210) 50
    Mar 07 265 (150) 115
    Apr 07 270 (130) 140
    May 07 275 (100) 175
    June 07 280 (60) 220
    July 07 285 (0) 285
    Aug 07 290 (0) 290
    Sept 07 295 150 445
    Oct 07 300 175 475
    Nov 07 305 175 480
    Dec 07 310 350 660
    Jan 08
    Feb 08
    Mar 08
    Apr 08
    May 08
    June 08
    July 08
    Aug 08
    Sept 08
    Oct 08
    Nov 08
    Dec 08

    By continuing the calculation, the answers you need appear in the last 5 rows of the table. Once you see the pattern, there are short-cuts but this is probably the simplest and most reliable way.

    Apologies if the 3 columns of figures in the table are not well spaced, but this idiotic website removes spaces from the messages you type in.

    Hope this helps!

    (PS. Questions like this are usually posted in the Student Discussion / Technician / Diploma forum, not the Chat forum.)

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