what is the standard deviation of a time series does the standard deviation of economic time series equal its level standard deviation is approximately proportional to its level. why is normal standard deviation of a period approximately constant what is standard deviation of a time series what is standard deviation of a time series why is the standard deviation for time series constant which statement best describes the concept of a standard deviation? what is the standard deviation for economic time series how is standard deviation proportional? how is standard deviation of a time series determined what is the standard deviation of the standard deviation if the standard deviation of a time series is approximately proportional to its level, that is, the standard deviation is well expressed as a percentage of the level of the series what is the standard deviation of a time series for a time series which condition is true for the standard deviation? if normal deviation is approximately proportional to level, what is standard deviation of time series what is standard deviation in rt what is standard deviation of a time series what does it mean if the standard deviation of a time series is approximately proportional to its level?