Exponential smoothing is meant to be used with time-series data when the data are made up of some or all of the basic components of level, trend, seasonality, and error. If the data series only fluctuates about an average with no trend and no seasonality, which form of smoothing would you employ?

If m∠abc = 70°, what is m∠abd? justify your reasoning.  using the addition property of equality, 40 + 70 = 110, so m∠abd = 110°.  using the subtraction property of equality, 70 − 30 = 40, so m∠abd = 30°.  using the angle addition postulate, 40 + m∠abd = 70. so, m∠abd = 30° using the subtraction property of equality.  using the angle addition postulate, 40 + 70 = m∠abd. so, m∠abd = 110° using the addition property of equality.