The data below is from the last 10 refuelings of my car Dete
     The data below is from the last 10 refuelings of my car. Determine the average gas mileage (in miles/gallon) and the variance in the gas mileage (miles/gallon)^2  Use this data to sketch a control chart for the gas mileage data including values for the UCL and LCL. Examine the distribution of data points and determine whether or not this process is \"in control\" and state why or why not.  If I define an Upper Specification Limit of 33 mpg and a Lower Specification Limit of 27.5 mpg, what are the values of C_P and C_PK? Based on these values, state why or why not the process is \"Six Sigma.\"  Miles  Gallons  400  13.346  364.7  11.335  401.9  12.469  349.5  11.852  393.8  13.2  341.5  10.482  347  11.381  416.7  14.312  346.1  11.394  410.9  13.312    
 
  
  Solution
Link to excel solution file : https://drive.google.com/open?id=0Byr5t30kJhKZbnRHazNXbWZzdms
| Miles | Gallon | Mileage | Average | 30.71272 | |
| 400 | 13.346 | 29.97153 | Standard Deviation | 1.161479 | |
| 364.7 | 11.335 | 32.17468 | Variance | 1.349034 | |
| 401.9 | 12.469 | 32.23194 | |||
| 349.5 | 11.852 | 29.48869 | USL | 33 | |
| 393.8 | 13.2 | 29.83333 | LSL | 27.5 | |
| 341.5 | 10.482 | 32.57966 | Z USL | 0.656428 | |
| 347 | 11.381 | 30.48941 | Z LSL | 0.922019 | |
| 416.7 | 14.312 | 29.11543 | Cp | 0.789224 | |
| 346.1 | 11.394 | 30.37564 | Cpk | 0.656428 | |
| 410.9 | 13.312 | 30.86689 |  | 

