You have taken three temperature readings 55∘F,50∘F and 58∘F. What is the range? The average range of a process is 3.50. The number of observations in subgroup is 3 . Calculate the UCLr. The grand average of all subgroup values is 60.237. The number of observations in subgroup is 3. Use the range in question Calculate the UCLx and LCLx.