Question

In a process control study, the overall process average over 15 samples is 63.45 with an average corresponding range of 5.6. What is the lower control limit of the R-chart

Answer 1

`LCL=1.94`

Explanation:

From the question we are told that:

Sample size
`n=15`

Mean
`\=x=63.45`

Range
`R=5.6`

Generally at
`n=15`

Value of Control chart constant,

`LCL=D*R`

Generally the equation for Lower Control Limit is mathematically given by

`LCL=D*R`

`LCL= 0.347*5.6`

`LCL=1.94`