The data in the Table are temperature readings from a chemical process in C degrees, taken every two minutes. (Read the observations down, from left.) The target value for the mean is 0 = 953.

Chemical ProcessTemperature Data

959

939

948

958

963

973

949

942

965

a. Apply an EWMA control chart to these data using = 0.2 and L = 3. Calculate the first two Upper and Lower limits and then the stable state limits.

b. Interpret the chart.