A motorcycle manufacturer produces the parts for its vehicles in different locations and transports them to its plant for assembly.To keep the assembly operations running efficiently,it is vital that all parts be within specification limits.One important part used in the assembly is the engine camshaft,and one important quality characteristic is the case hardness depth.Specifications state that the hardness depth must be between 3.0 mm and 6.0 mm.To investigate the process,the quality control engineer selected 25 daily subgroups of n = 5 and measured the hardness depth.The process yielded a mean of the means = 4.50 and an average range = 1.01.Calculate the center line for the X-bar chart.
A)1.01
B)4.50
C)3.49
D)0.90

Question

A motorcycle manufacturer produces the parts for its vehicles in different locations and transports them to its plant for assembly.To keep the assembly operations running efficiently,it is vital that all parts be within specification limits.One important part used in the assembly is the engine camshaft,and one important quality characteristic is the case hardness depth.Specifications state that the hardness depth must be between 3.0 mm and 6.0 mm.To investigate the process,the quality control engineer selected 25 daily subgroups of n = 5 and measured the hardness depth.The process yielded a mean of the means  = 4.50 and an average range = 1.01.Calculate the center line for the X-bar chart.
A)1.01 
B)4.50 
C)3.49 
D)0.90

Quizplus · Accepted Answer

The center line for the X-bar chart is the mean of the process, which is given as 4.50 in this case. Therefore, the correct answer is B. The range, which is 1.01, is used to calculate control limits for the chart, but it is not used to determine the center line.

A Motorcycle Manufacturer Produces the Parts for Its Vehicles in Different