The effect of the time of day a psychology class is taught on test scores is being studied in an experiment. The difficulty of test questions has been identified as an extraneous factor that could also affect test scores. How can the difficulty of test questions best be addressed to minimize its effect in the experiment? A. Direct control by requiring every class to take the same test B. Blocking into groups based on the teacher of the class C. Replication of the experiment at different times of the year D. Randomization of students in morning and afternoon classes P. S if anyone knows prob and stats I need help really bad

Ican interpret and represent the remainder in division calculations sensibly for the context (eg if we wont to know how many 40 seat buses will be needed to transport 170 students for on excursion, we divide 170 by 40 and realise buses and another smaller vehicle to that we need 4 transport 10 more students) solve the following questions. show your work! 11) the zoo had 420 butterflies that needed to be transported to a new enclosure. the boxes that the butterflies would be moved in only hold 80 butterflies in each. how many boxes would they need? 2 12) each classroom in the school can have exactly 25 students, if there are 345 students in the school how many full classrooms are there?