STATS

 Please read the abstract of the article (https://www.nejm.org/doi/full/10.1056/NEJMoa2034577) inthe New England Journal of the Medicine. Then answer the following questions.a. What are the two groups being compared? Be as specic as possible. (Skim the TrialProcedures subsection copied below as well. )Trial ProceduresWith the use of an interactive Web-based system, participants in the trial were randomly assignedin a 1:1 ratio to receive 30 g of BNT162b2 (0.3 ml volume per dose) or saline placebo.Participants received two injections, 21 days apart, of either BNT162b2 or placebo, delivered inthe deltoid muscle. Site sta who were responsible for safety evaluation and were unaware ofgroup assignments observed participants for 30 minutes after vaccination for any acutereactions.b. What is the primary outcome or response variable?c. Based on the results (copied below), calculate a p-value for testing whether the vaccine iseective against COVID. Be sure to prepare, check, calculate and conclude. What is thesmallest signicance level at which you could conclude that the vaccine is eective?ResultsA total of 43,548 participants underwent randomization, of whom 43,448 received injections:21,720 with BNT162b2 and 21,728 with placebo. There were 8 cases of Covid-19 with onset atleast 7 days after the second dose among participants assigned to receive BNT162b2 and 162cases among those assigned to placebod. The study was only observer blind meaning that those charged with measuring, recordingand assessing changes in study participants are blinded to which group a patient isassigned to. Dene a double blind study and how could the lack of double blinding aectresults in a study such as this? Would it over-estimate or under-estimate the benet of thevaccine? Explain.