Time-series Graphs Flashcards
1
Q
What is different about a time series graph compared to a regular line graph?
A
- Scales don’t have to start at 0
- Points plotted with crosses
- Time is on the x axis
2
Q
Finish the sentence:
“In a time series graph, values above/below the TREND LINE are…”
A
More/less than the trend would suggest
3
Q
What three things can a trend line show?
A
Rising/falling/level trend
4
Q
Where is the trend line drawn?
A
Halfway between highest and lowest point
5
Q
Finish the sentence:
” Variation in a time series may be…”
A
- General trend shown by trend line
2. Seasonal variation
6
Q
What is seasonal variation?
A
Repeating patterns of variation
7
Q
What is a moving average?
A
Average worked out for a giving number of successive observations in a cycle
8
Q
How do we plot moving averages?`
A
- Plot at MIDPOINT of the time intervals they cover
2. With a different symbol
9
Q
How do we calculate the moving average?
A
1st point = O1 + O2 +….On
2nd point = O2 + O3 +…On
