A design engineer wants to construct a sample mean chart for controlling the service life of a halogen headlamp his company produces. He has the following sample data available and knows his long term sample mean has been about 500 hours. Sample Service Life (Hours)
Sample 1 - 495, 500, 505, 500
Sample 2 - 525, 515, 505, 515
Sample3 - 490, 500, 480, 490
1) What is the mean of sample means?
2) What is the sample mean for sample #2
3) For a mean chart, what is the UCL?
4) What is the LCL?
5) If the specification is for engine life to be at least 475 hours, what is the Cpk? Use one decimal place.