A marketing firm needs to replace its existing network provider and is considering three different providers. A primary consideration is the amount of system downtime. The following table contains the amount of network downtime (in hours) for the last five months for each network provider. Using the critical value approach and α = 0.05, the appropriate conclusion is ________.
A) reject the null hypothesis, we cannot conclude not all median network downtimes are equal
B) do not reject the null hypothesis, we cannot conclude not all median network downtimes are equal
C) reject the null hypothesis, we can conclude not all median network downtimes are equal
D) do not reject the null hypothesis, we can conclude not all median network downtimes are equal

Question

A marketing firm needs to replace its existing network provider and is considering three different providers. A primary consideration is the amount of system downtime. The following table contains the amount of network downtime (in hours) for the last five months for each network provider.  Using the critical value approach and α = 0.05, the appropriate conclusion is ________.
A) reject the null hypothesis, we cannot conclude not all median network downtimes are equal 
B) do not reject the null hypothesis, we cannot conclude not all median network downtimes are equal 
C) reject the null hypothesis, we can conclude not all median network downtimes are equal 
D) do not reject the null hypothesis, we can conclude not all median network downtimes are equal

Quizplus · Accepted Answer

The appropriate statistical test to use in this scenario is the Kruskal-Wallis test, as we are comparing the medians of three or more independent groups. Using the critical value approach and α = 0.05, the calculated test statistic of 6.15 exceeds the critical value of 5.99 (for three groups at α = 0.05). This means we reject the null hypothesis and can conclude that not all median network downtimes are equal among the three providers.

A Marketing Firm Needs to Replace Its Existing Network Provider