A manufacturer of television sets is interested in the effect of tube conductivity of four different types of coating for color picture tubes. A completely randomized experiment is conducted and the following conductivity data are obtained:Coating Type Conductivity1 143 141 150 1462 152 149 137 1433 134 136 132 1274 129 127 132 129a. Is there a difference in conductivity due to coating type? Use α = 0.05b. Estimate the overall mean and the treatment effects. c. Compute a 95 percent interval estimate of the mean of coating type 4. Compute a 99 percent interval estimate of the mean difference between coating types 1 and 4.d. Use the graphical method discussed in Section 3.5.3 to compare the means. Which coating produces the highest conductivity?e. Assuming that coating type 4 is currently in use, what are your recommendations to the manufacturer? (We wish to minimize conductivity.)f. Analyze the residuals from the fitted model and draw your conclusions about the model adequacy.