Final answer:
The characteristics of level, trend, and variability in time-series designs are explained.
Step-by-step explanation:
The characteristics of level, trend, and variability in time-series designs:
1) Level
The level refers to the average value or baseline of the data over a period of time. It represents the overall central tendency of the time series.
2) Trend
The trend describes the long-term pattern or direction of the data. It shows whether the data is increasing, decreasing, or staying relatively constant over time.
3) Variability
Variability refers to the amount of fluctuation or dispersion in the data. It represents the extent to which the values deviate from the average or trend.