I need help with this problem please

Quality control engineers fire tiles made with this new material at three different temperature settings (1500.F, 1800 F and 2200F) and for four different times (2 hours, 6 hours, 10 hours and 12 hours) to determine the optimal parameter settings for firing that will result in tiles with high flexural strength. The response variable in this experiment is O firing temperature. O the new material. O tiles. flexural strength. O firing time. D Question 11 1 ptsWhich is not a critical part of designing a good experiment? Control of known sources of variability. Replication of the on a sufficient number of subjects. O Random selection of subjects. Random assignment of subjects to treatments. O All of these are important.D Question 12 1 pts An education researcher was interested in examining the effect of the teaching method and the effect of the particular teacher on students' scores on a reading test. In a study, there are four different teachers (Juliana, Felix, Sonia, and Helen) and three different teaching methods (method A, method B, and method C). The number of students participating in the study is 258. Students are randomly assigned to a teaching method and teacher. Identify the factor(s) in the experiment. O The education researcher O Teaching method and teacher O Juliana, Felix, Sonia, and Helen O Method A, method B, method C Score on reading testAn education researcher was interested in examining the effect of the teaching method and the effect of the particular teacher on students' scores on a reading test. In a study, there are four different teachers (Juliana, Felix, Sonia, and Helen) and three different teaching methods (method A, method B, and method C). The number of students participating in the study is 258. Students are randomly assigned to a teaching method and teacher. Identify the levels of the factor "teaching method." O Teaching method and teacher O Juliana, Felix, Sonia, and Helen The education researcher Score on reading test Method A, method B, method CD Question 14 1 pts A Columbia University study linked soda consumption to behavior problems in children. Researchers examined data from a previous study that followed 2929 mother-child pairs. One survey asked about behaviors of the child and also about soda consumption. They found that the more soda the kids drank, the more behavior problems they had. What aspect of a well-designed experiment is absent from this study? O blinding O a placebo O randomization O a control group O all of theseWhich is true about randomized experiments? 1. Randomization reduces the effects of confounding variables. Il. Random assignment of treatments allows results to be generalized to the larger population. Ill. Blocking can be used to reduce the within-treatment variability. O I only O II only O Ill only O I and III O I, II, and Ill