what is the average gradation for a time series when to use a variance chart how do you normalise a time series what is gradation range what is the normal range of a quality control chart why is a quality control chart a problem what is the normal range of a sample why is the variance higher in a time series how to calculate variance between different ranges what is the range of a grading interval gradation range for time series what gradation does lcl show? why are variances higher in a data point what is the gradation range what is the range for a data point in a normal distributed data set why should the interval be between 0 and 1 in QCT what is a standard range for the quality control chart when a gradation is used to normalise a data set, how does it impact the variance? i am trying to normalise time series data for what data what is variance range