The thickness of a printed circuit board is an important quality parameter. Data on board thickness (in inches) are given in the following table for 25 samples of three boards each. (Please refer to the excel file for the data.)Samplex1x2x310.06290.06360.06 420.06300.06310.062230.06280.06310. 063340.06340.0630.063150.06190.0628 0.06360.06130.06290.063470.06300.06 390.062580.06280.06270.062290.06230 .06260.0633100.06310.06310.0633110. 06350.0630.0638120.06230.0630.06313 0.06350.06310.063140.06450.0640.063 1150.06190.06440.0632160.06310.0627 0.063170.06160.06230.0631180.06300. 0630.0626190.06360.06310.0629200.06 400.06350.0629210.06280.06250.06162 20.06150.06250.0619230.06300.06320. 063240.06350.06290.0635250.06230.06 290.063a. Set up x-bar and R control charts for a=0.0027. Is the process in statistical control? Please draw a plot. b. Set up x-bar and S control chart, and compare the S chart with the R chart in part (a). Please draw a plot. Hint: In this case, you should re-estimate the variance of x-bar and re-calculate the x-bar chart.