QUESTION 4 You are studying the concentration of antibody titers for Rubella (a disease) in people with and without HIV. You manage to study 11 healthy people and 7 people with HIV. Select the answer that most correctly describes the null hypothesis (HO) and the alternative hypothesis (H1) for this research question. O HO: population mean Rubella antibody titer level in people with HIV = population mean Rubella antibody titer level in people without HIV H1: population mean Rubella antibody titer level in people with HIV > population mean Rubella antibody titer level in people without HIV HO: sample mean Rubella antibody titer level in these 7 people with HIV = sample mean Rubella antibody titer level in these 11 people without HIV H1: sample mean Rubella antibody titer level in these 7 people with HIV DOES NOT = sample mean Rubella antibody titer level in these 11 people without HIV O HO: population mean Rubella antibody titer level in people with HIV = population mean Rubella antibody titer level in people without HIV H1: population mean Rubella antibody titer level in people with HIV