Construct An $\bar { x }$ Chart and Determine Whether the Process Variation Is Within Statistical

question 143

Essay

Construct an $\bar { x }$ chart and determine whether the process variation is within statistical control.
$\text { Control Chart Constants }$
$\begin{array}{ccccccc}&\bar{x}&&s&&R\\\hline n & A_{2} & A_{3} & B_{3} & B_{4} & D_{3} & D_{4} \\\hline 2 & 1.880 & 2.659 & 0.000 & 3.267 & 0.000 & 3.267 \\3 & 1.023 & 1.954 & 0.000 & 2.568 & 0.000 & 2.574 \\4 & 0.729 & 1.628 & 0.000 & 2.266 & 0.000 & 2.282 \\5 & 0.577 & 1.427 & 0.000 & 2.089 & 0.000 & 2.114 \\6 & 0.483 & 1.287 & 0.030 & 1.970 & 0.000 & 2.004 \\7 & 0.419 & 1.182 & 0.118 & 1.882 & 0.076 & 1.924 \\8 & 0.373 & 1.099 & 0.185 & 1.815 & 0.136 & 1.864 \\9 & 0.337 & 1.032 & 0.239 & 1.761 & 0.184 & 1.816 \\10 & 0.308 & 0.975 & 0.284 & 1.716 & 0.223 & 1.777 \\\hline\end{array}$
A machine that is supposed to produce ball bearings with a diameter of 7 millimeters yields the following data from a test of 5 ball bearings every 20 minutes.
$\begin{array}{l|lllll|l|l}\text { Sample } &&&{\text { Ball Bearing Diameter (mm) }} &&& \overline{\boldsymbol{x}} & \text { Range } \\\hline 1 & 6.3 & 6.8 & 6.9 & 6.8 & 6.9 & 6.74 & 0.6 \\2 & 6.3 & 6.6 & 6.6 & 6.3 & 7.0 & 6.56 & 0.7 \\3 & 6.8 & 6.7 & 7.0 & 6.5 & 7.0 & 6.80 & 0.5 \\4 & 7.0 & 6.7 & 6.7 & 6.8 & 6.8 & 6.80 & 0.3 \\5 & 6.8 & 6.8 & 6.6 & 6.5 & 6.4 & 6.62 & 0.4 \\6 & 6.8 & 6.7 & 6.6 & 6.3 & 6.9 & 6.66 & 0.6 \\7 & 7.3 & 7.3 & 7.4 & 7.4 & 7.0 & 7.28 & 0.4 \\8 & 7.2 & 7.0 & 7.2 & 6.9 & 7.1 & 7.08 & 0.3 \\9 & 7.3 & 7.6 & 7.1 & 7.4 & 7.6 & 7.40 & 0.5 \\10 & 7.2 & 7.6 & 7.5 & 7.6 & 7.1 & 7.40 & 0.5 \\11 & 7.2 & 7.2 & 7.4 & 7.0 & 7.0 & 7.16 & 0.4 \\12 & 7.5 & 7.4 & 7.4 & 7.6 & 7.1 & 7.40 & 0.5\end{array}$

---

Definitions:

Reproductive Advantage

A genetic or behavioral characteristic that increases an organism's likelihood of successful reproduction and passing genes to subsequent generations.

Natural Selection

The process through which traits that enhance survival and reproduction become more common in successive generations of a population.

Human Genome

The complete set of nucleic acid sequences for humans, encoded as DNA within the 23 chromosome pairs in cell nuclei and in a small DNA molecule found within individual mitochondria.

Genetic Profile

A summary of an individual's unique genetic characteristics, often used for identification or assessing disease risk.