The Weidmann Group Companies, with headquarters in Rapperswil, Switzerland, are worldwide leaders in insulation systems technology for power and distribution transformers. One facet of its expertise is the development of dielectric fluids in electrical equipment. Mineral oil–based dielectric fluids have been used more extensively than other dielectric fluids.

Their only shortcomings are their relatively low flash and fire point. One study examined the fire point of mineral oil, high-molecular-weight hydrocarbon

(HMWH), and silicone. The fire points for each of these fluids were as follows:

Fluid Fire Points (°C)
Mineral Oil 162 151 168 165 169 HMWH 312 310 300 311 308 Silicone 343 337 345 345 337

a. Develop the appropriate ANOVA table to determine if there is a difference in the average fire points among the types of dielectric fluids. Use a significance level of 0.05.

b. If warranted, use the Tukey-Kramer procedure to determine which populations have different mean fire points. Use an experiment-wide error rate of 0.05.