Diarrhea can kill children and is often caused by rotavirus. Read the abstract below, and answer the questions that follow.
"Methods: We obtained data on deaths from diarrhea, regard less of cause, from January 2003 through May 2009 in Mexican children under 5 years of age. We compared diarrhea related mortality in 2008 and during the 2008 and 2009 rotavirus seasons with the mortality at baseline (2003-2006), before the introduction of the rotavirus vaccine. Vaccine coverage was estimated from administrative data. Conclusions: After the introduction of a rotavirus vaccine, a significant decline in diarrhea-related deaths among Mexican children was observed, suggesting a potential benefit from rotavirus vaccination."*
a. State the death rate before vaccine and the death rate after vaccine.
What was the change in deaths per 100,000 children? From the given p-value, can you reject the null hypothesis of no change in death rate?
b. Would you conclude that the vaccine was effective? Why or why not?