1. GCSE Statistics
Time Series

2. a
a trend line can be shown how data changes over a period of time
It may show:
a) rising trend
b) falling trend
c) level trend (this was as close as I could get)
don’t use the word correlation – these are not scatter graphs b c

3. Seasonal Variation
A seasonal variation is a pattern that repeats in the time series
here we can see the price of kiwi fruit rises substantially in March.

4. Here the level of CO2 at Mauna Loa falls dramatically in the fourth quarter although the data indicates a rising trend

5. These are gingerbread-maple moon pies
These are gingerbread-maple moon pies. A seasonal variation on homemade moon pies and nothing to do with the course at all apart from being an example of where seasonal variation effects everyday life 

6. To draw a trend line, put a ruler on the graph and move it until the areas enclosed either side of the ruler are equal.
This will be roughly half way between the highest and lowest point for each year.
Now draw your trend line.

7. Yes that is all there is to it!
Your Turn
exercise 6C page 215
exercise 6D page 218
need help?