1.) A company has been tasked with evaluating how effective a new type of aspirin is at treating atherosclerosis. or coronary artery plaque build-up. The evaluators will measure four different concentrations of acetylsalicylic acid in the new brand of aspirin:0 milligrams 75 milligrams. 31 milligrams and 100 milligrams. An equal number of volunteers will be placed into 20 different treatment cohorts. Each cohort will be prescribed one of the four aspirins, and the evaluators will record the amount of plaque build-up in each volunteer's coronary arteries both before and after three months of using the prescribed medication

a.) State the treatments, experimental units, and response variable for this experiment.

b.) Did this experiment have a control group? Justify your answer.

c.) Describe a method to randomly assign the treatments to the experimental units so that each of the treatments has the same number of units.