Hi, For question 5.1, I am curious how we can derive the points shown in the solution from the table given.
Hi 7788, Is there a particular point you are curious / confused about? These are suggested points (themes) in the scene addressing the issue of the increase in the number of complaints. The "1 in 12" point is taken from the 10th row of the table. As indicated in the solutions, it would be distracting and/or potentially confusing to refer to the underlying assumptions (eg the choice of statistical distribution), or information based on other confidence intervals. Therefore most of the data/information in the table has not been used. Hope helpful Michael
The third suggested theme in the solution is to tell the marketing director that the 50% increase is not significant i.e. the numbers will naturally fluctuate month to month and there is a reasonable chance, 1 in 12, of seeing 9 complaints. The fourth point has been suggested to get the point across that a repeat/trend of complaints at this level due to random fluctuations is less likely (and might therefore indicate an underlying problem). These points combined with points 1 and 2 should be sufficient to address the marketing manager's issue. Thanks Michael
