About 25% of people that test positive for Covid-19 are vaccinated for Covid-19. Define the r.v. Xi to be 1 if someone that tests positive is vaccinated and 0 if they are not vaccinated. Suppose 3 people have tested positive for Covid-19 (independently of each other). Let T denote the number of people that are vaccinated amongst the 3 that tested positive. (1) Using the r.v.’s Xi, write a mathematical equation for calculating T. (2) What is the expected value of T? (3) What is the variance of T? (4) What is the probability distribution of T?