7'25 III LTE [1' Take Quiz Exit D Question 9 3.33 pts I would like to explore what the annual average salary of the MSU faculties is. To that end, | ask 20 professors how much money they earn per year. The results showed that they earn 80K on average annually with the standard deviation of 20K. If I would like to determine a 95% condence interval for the true average annual salary which test should I use? 0 t-test, because the population standard deviation is unknown 0 t-test, because the population standard deviation is known 0 z-test, because the population standard deviation is known 0 z-test, because the population standard deviation is unknown D Question 10 3.33 pts You would IIEP tn see whet-"Her nennle living