Dolce Soap is conducting a study to assess the capability of its 250-gram bar soap production line. As a part of study, 20 samples of 4 were collected by the quality assurance group and the observation were recorded (table below). A critical quality measure is the weight of the soap bars after stamping. The upper and lower tolerance limits are 245 and 255 grams, respectively. Sample Obs.1 1 2 3 4 56 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Obs.2 Obs.3 248,40 249,70 253,30 245,70 249,10 248,40 252,90 250,90 249,50 247,80 251,40 244,90 251,00 249,90 249,20 252,40 249,60 252,20 249,40 247,50 246,90 250,60 248,90 250,00 246,50 244,60 249,00 248,60 250,20 246,20 249,10 250,50 249,50 250,90 246,80 248,60 246,00 253,80 246,90 247,70 246,50 249,30 252,20 250,70 250,70 248,80 249,20 248,20 249,30 247,70 249,40 247,20 250,40 248,60 254,10 250,60 252,10 248,00 250,40 249,40 250,60 249,20 245,80 249,80 246,00 251,20 248,30 249,50 251,40 247,60 249,10 248,20 250,20 248,50 Obs.4 247,00 249,60 247,50 247,50 251,90 249,80 a. Draw the control charts for the data obtained and verify that the process is in statistical control b. Calculate Cpk and Cp values for the current process and comment its capability based on three-sigma quality standard firm is seeking c. If production would be able to improve the process standard deviation to 1,50 grams, how would your comments change (include re-calculate Cpk and Cp values to your answer) d. What kind of changes would be needed to a current process if customers wanted four-sigma quality