please be careful with these kind of questions becasue sometimes i get them wrong

thank you

Question 27 (5 points) Which of the following could be a cause of a favorable direct materials variance. (Select all that apply) Purchasing negotiated a more favorable purchasing agreement Assembly line workers are more experienced Assembly line workers are less experiences Poor quality materials Question 28 (5 points) Which of the following could cause a favorable labor efficiency variance? Click all that apply. Equipment failures More experienced assembly line workers Less experienced assembly line workers Poor quality materials Which of the following would be a cause of a favorable direct materials efficiency variance. More experienced assembly line workers Lower quality materials Equipment failures Higher quality materials Question 30 (5 points) Who is responsible for setting the cost standard for direct labor? Human resources manager Purchasing manager Production manager and engineers Production managers