For each of the following exercises, use the

Chapter 13, Problem 26E

(choose chapter or problem)

For each of the following exercises, use the previous data to complete these parts.

(a) Apply Fisher’s LSD method with \(\alpha=0.05\)  and determine which levels of the factor differ.

(b) Use the graphical method to compare means described in this section and compare your conclusions to those from Fisher’s LSD method.

Preparation method in Exercise 13-12. Use \(\alpha=0.05\)

An article in the Materials Research Bulletin [1991, Vol. 26(11)] investigated four different methods of preparing the superconducting compound \(\mathrm{Pb} \mathrm{Mo}_{6} \mathrm{~S}_{8}\) The authors contend that the presence of oxygen during the preparation process affects the material’s superconducting transition temperature Tc. Preparation methods 1 and 2 use techniques that are designed to eliminate the presence of oxygen, and methods 3 and 4 allow oxygen to be present. Five observations on \(\mathrm{T}_{\mathrm{c}}\)

 (in \({ }^{\circ} \mathrm{K}\)) were made for each method, and the results are as follows:

(a) Is there evidence to support the claim that the presence of oxygen during preparation affects the mean transition temperature? Use \(\alpha=0.05\)

(b) What is the \(P \text {-value }\) for the \(\text { F-test }\)  in part (a)?

(c) Analyze the residuals from this experiment.

(d) Find a \(95 \%\) confidence interval on mean \(\mathrm{T}_{\mathrm{c}}\) when method 1 is used to prepare the material.

Equation Transcription:

   

Text Transcription:

\alpha=0.05

\alpha=0.05

PbMo6S8

Tc

°K

\alpha=0.05

P-value  

F-statistic

95%

Tc