why is it important to make nonstationary data stationary what is stationarity assumption in a graph why do we need stationary what is the stationarity assumption why is stationarity important why is stationarity requirement important how to do the stationarity requirement what is the stationarity assumption why is stationarity important why it is important to convert non stationary data into stationary why is stationarity required for non stationary data when does the stationarity assumption need to be made why is stationarity requirement necessary what is the stationary assumption why is it important to make non stationary data a stationary object? what is required to use nonstationary data in statistical analysis when to make stationarity assumptions what is stationarity why is stationarity requirement important why is stationarity assumption necessary