EngrExpt (version 0.1-6)

bath: Electrical resistance after water bath

Description

In a production process the product passes through a water bath. In this experiment the time spent in the bath and the temperature of the bath were varied to determine their effect on the electrical resistance of the final product.

References

Peter R. Nelson, Marie Coffin and Karen A. F. Copeland (2003), Introductory Statistics for Engineering Experimentation, Elsevier. (Appendix A)

Examples

str(bath)
dotplot(ordered(time) ~ er, bath, groups = temp, type = c("p","a"),
        xlab = expression("Electrical resistance (ohm/" * m^2 * ")"),
        ylab = "Time in bath (coded)",
        auto.key = list(columns = 2, lines = TRUE))
summary(fm1 <- lm(er ~ time * temp, bath))
summary(fm2 <- lm(er ~ time + temp, bath))
summary(fm3 <- lm(er ~ temp, bath))