Question

a small value of the smoothing constant is preferred when the time series contains select. select relatively little random variability stable data substantial random variability a small mean square error

Explanation:

In exponential smoothing, a small smoothing constant (α) is used when the time series has substantial random variability. A small α gives more weight to past observations, which helps smooth out the large random fluctuations. For relatively little random variability or stable data, a larger α might be used. Mean square error is a measure of forecast accuracy, not a characteristic of the time series that determines the smoothing constant choice.

Answer:

substantial random variability