Cube Quality Control

Today’s consumers are constantly trying to judge the quality of products. But what is quality? How and by whom is quality determined? Some would say the designer creates specifications, which in turn dictate the quality of a product. That quality is also based on the acceptable value of a part within a whole product. Statistics are commonly used in manufacturing processes to control and maintain quality.

This activity will allow you to apply statistics in order to analyze and determine the quality (as measured by the consistency of the size) of wooden cubes. The wooden cubes will be used in the upcoming Puzzle Cube Challenge. You will design and construct a puzzle cube as part of the challenge. The consistency in size of the wooden cubes will affect the quality of your final product.
 

Equipment

·         Engineering notebook

·         Pencil

·         Dial caliper

·         27 wooden cubes per student

 

Procedure

  

1. Each of you will receive a set of 27 wooden cubes (3/4 in.). Label each cube (1 through 27) lightly in pencil. Measure the side length of each block along the grain. When taking a measurement, position the block so the caliper measuring surfaces are touching the end grain faces. Record the measurements to create a data set. For this analysis a precision of .001 is necessary; therefore, record each measurement to the nearest one thousandth of an inch (.001 in).

2. Use Excel to perform a statistical analysis of the data to determine each of the following: Mean, Median, Mode, and Standard Deviation.                   

Create a histogram to represent the data. Use seven to ten class intervals (bin values). Be sure to label your axes and define units where appropriate.

 

 3.    Does your data appear to be normally distributed? Justify your answer.