Example 5.8Five samples are taken from a normal population of parts from a factory with average = 3 and CT = 1. The samples are 2.0, 2.5, 3.0, 3.5, and 4.0. Does this sample of parts support the belie...

The statistical relationships of the sample and population averages have been discussed in previous sections. There is a similar distribution for the sample variability s2, which can be used to learn...

Engineers have found the use of the confidence percentage discussed in the last section for estimating the average or average rather unfamiliar. They are more comfortable with the concept of the confi...

An engineer uses 100 samples to check the average noise output of amplifiers (in Db) produced in the production line. If it is known that the line is normally distributed with standard deviation of th...

The previous section has introduced some statistical terms that are not widely used by engineers but are very familiar to statisticians. This section is a review of some of the statistical terms and p...

Example 5.1A manufacturing line produces resistors in a normal process with an average value of 500 ohms. A Sample of nine resistors were taken from yesterday^ production, with sample average = 540 oh...

The knowledge of certain properties of a subset (sample), can be used to draw conclusions about the properties of the whole set (populations). Properties can be of two types, as discussed in earlier c...

One of the concerns about using six sigma is the volume of production. There are two parts to this concern. The immediate reaction is that the 3.4 PPM defect rate associated with six sigma might imply...