Random Samples of 4 Items Are Selected from a Manufacturing $\Sigma$

question 113

Multiple Choice

Random samples of 4 items are selected from a manufacturing process at regular intervals and a certain quality characteristic is measured. After 25 samples, $\Sigma$ X = 15,350 and $\Sigma$ R = 411.4
To construct a range chart, what is the lower control limit (LCL) for the range?

• A) 602.004
• B) 411.400
• C) 625.666
• D) 0.00

---

Definitions:

Confidence Interval

A range of values, derived from sample statistics, that is likely to contain the value of an unknown population parameter with a specified level of confidence.

Expected Value

The long-run average value of a random variable over many independent trials.

Simple Linear Regression

A method used in statistics to quantify and analyze the linear relationship between two quantitative variables, specifically one predictor and one response variable.

Confidence Interval

A range of values, derived from sample statistics, that is likely to contain the value of an unknown population parameter, with a certain level of confidence.