Question

A new vaccine was tested to see if it could prevent the ear infections that many infants suffer from Babies about a year old were randomly divided into two groups. One group received vaccinations, and the other did not. The following year, only 374 of 2457 vaccinated children had ear infections, compared to 457 of 2452 unvaccinated children. A positive 99.9% confidence interval for the difference in the rates of ear infection was used to examine the effectiveness of a vaccine against ear infections in babies and was found to be (-0.1% 6.9%). Suppose that instead you had conducted a hypothesis test. Complete parts a through e below without actually doing the test a) Let Py represent the true proportion of vaccinated children who had ear infections and pay represent the true proportion of unvaccinated children who had ear infections. What hypotheses would you test? OA HP - Phy0 HA PV - PNV 0 OC. Ho Dy - Prvo HA PvPNV > O E. Ho Pv-Pnv = 0 HA Pv - PNV 0 OB. HPV- PO HA PVP >0 OD. Ho: PV - Pw0 HA PV-PNVO OF He: PV- Po HA PVPN 0 b) State a conclusion based on the given confidence interval. Choose the correct answer below. R inth a ththar Thule Click to select your answer(s)

Answer 1

| Answer & - - El Ho : Pv - PNV =0 MA : Pv - PNV LO Ć] Because o is in the confidence interval. fail to revect the null hypothesis. There is not sufficient evidence to conclude that the vaccine reduces the rate of ear infections. C1 - here 1-2 =99.9% Haz 0.999 Q: 0.001 2-0.1% d] - Type I error accepting the Ho when Ha is true. f it is because here we type I error. es_ → c] Babies would be missing out on effective vaccinations.