Which type of study best describes the following research most likely to be done?

a teacher wants to know how fast all her students for a particular period can complete a multiplication quiz to check their mental math abilities. so, all of her students are tested on a computer and the time of each and every student is recorded.

group of answer choices

experimental study

observational study

simulation study

census

sampling

Question b of 10which of the following describe an angle with a vertex at a? check all that applyo a. labcов. савd dooo c_baco d. zacb

The investigating team suspected that there were differences in the cost of repairing cars in workshop i and workshop ii. the investigating team suspected that the costs raised by workshop i were greater than workshop ii. for that they tested the repair of 15 cars in each workshop to see the cost of repairs.the decision of the right hypothesis to prove the suspicion above is a. h0 : μ1- μ2­ = 0; ha : μ1- μ2­ ≠ 0 b. h0 : μ1- μ2 ≥ 0; ha : μ1- μ2 < 0 c. h0 : μd ≥ 0; ha : μd < 0 with μd = μ2- μ1 d. h0 : μd = 0; ha : μd ≠ 0 with μd = μ2- μ1 e. h0 : μ1- μ2 = 0; ha : μ1- μ2 ≥ 0

Me because i don't understand how to do it.: )