Circuit boards data
Number of nonconformities observed in 26 successive samples of 100 printed circuit boards. Sample 6 and 20 are outside the control limits. Sample 6 was examined by a new inspector and he did not recognize several type of nonconformities that could have been present. Furthermore, the unusually large number of nonconformities in sample 20 resulted from a temperature control problem in the wave soldering machine, which was subsequently repaired. The last 20 samples are further samples collected on inspection units (each formed by 100 boards).
data(circuit)
A data frame with 46 observations on the following 3 variables.
number of defectives in 100 printed circuit boards (inspection unit)
sample size
trial sample indicator (TRUE/FALSE)
Montgomery, D.C. (1991) Introduction to Statistical Quality Control, 2nd ed, New York, John Wiley & Sons, pp. 173–175
data(circuit) attach(circuit) summary(circuit) boxplot(x ~ trial) plot(x, type="b") detach(circuit)
Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.