Question

?The traditional retail store audit is one of the most widely used marketing research tools among consumer
package goods companies. It involves periodic audits of a sample of retail audits to monitor inventory and
purchases of a particular product. A study was conducted to compare market share data yielded by retail
store audits with two alternative, less costly auditing procedures – weekend selldown audits and store
purchases audits. The market shares of six major brands of beer distributed in eastern cities were
estimated using each of the three store auditing methods. The data are provided in the accompanying table.

Market Share (%) Traditional Store Audit 18.0 15.3 8.9 6.5 5.3 3.4 Weekend Selldown Audit 19.0 17.3 8.5 4.9 Store Purchases Audit 20.7 14.0 10.1 6.1 4.6 Beer Brand 2 4 3.0 Randomized blocks ANOVA Std. Dev Mean 9.5667 9.8000 9.7667 5.8322 Traditional Store Audit 6.7308 Weekend Selldown Audit 6.6656 Store Purchases Audit 19.2333 15.5333 9.1667 5.8333 5.3333 3.1667 1.3650 Block 1 1.6623 Block 2 0.8327 Block 3 0.8327 Block 4 0.7506 Block 5 0.2082 Block 6 6.0339 Total ANOVA table MS 0.0956 121.1396 1.3049 Source df ue 9299 92.84 4.77E-08 Treatments Blocks Error Total 0.191 605.698 13.049 618.938 0.07 10 17 Post hoc analysis Tukey simultaneous comparison t-values (df 10) Traditional Store Audit 9.5667 Store Purchases Audit Weekend Selldown Audit 9.8000 9.7667 Traditional Store Audit 9.5667 Store Purchases Audit 9.7667 Weekend Selldown Audit 9.8000 0.30 0.35 0.05 critical values for experimentwise error rate 0.05 0.01 2.74 3.73

5A. Using the Excel output provided and ? = .05, is there sufficient evidence to indicate a difference in
the mean estimates of beer-brand market shares produced by the three auditing methods? Do a
complete and appropriate hypothesis test using the 5-step procedure and p-value approach. If
and only if significant differences are found, perform the appropriate post hoc test and clearly and
briefly discuss your findings.

5B. Construct a 95% confidence interval estimate of the difference between the mean estimates of
beer-brand market shares produced by the traditional store audit and the weekend selldown audit.
Make sure that your confidence interval is in the correct final format, as discussed in class.
Interpret the practical meaning of the interval estimate, in plain English

Answer 1