Statistics Time Series Seasonal Effect

Identify how long the pattern is. What is the period of time it takes for the pattern to repeat? The season is a weekly (7 days) pattern.

Describe the highs and the lows in each pattern…. Highest sales always seem to occur on a Friday, where sales of between $290 000 and $250 000 have occurred. The weekly high values have decreased slightly over the four week period. Lowest sales of $100 000 or less have occurred on Saturdays and Sundays. These low values have not changed over the four week period.

Describe the absolute high and / or low over the entire time period. Over these 4 weeks the highest value of sales in one day was about $290 000, on the Friday of Week 1. The lowest value of sales was about $75 000 on Sunday, Week 3.

Describe what happens in between the high and low points.. Each week sales generally increase slowly from Monday through to Thursday. There is a large jump in sales on Fridays and a steep decline to Saturday’s sales figures.

Describe how consistent is the seasonal pattern from one week to the next… The seasonal pattern is very consistent from week to week

Always, always put Dates Values Context (units) in your writing

Summary Identify how long the pattern is. Describe the highs and the lows in each pattern…. Describe the absolute high and / or low over the entire time period. Describe what happens in between the high and low points. Describe how consistent is the seasonal pattern from one week to the next…

Now add comments on seasonal effects to your Export of Dairy Products time series