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Could someone me with number one you

Researchers randomly divide participants into groups. each group takes a different amount of omega-3 fatty acid supplements daily for a month. one group receives a placebo. the researchers measure the impact on cholesterol levels in the blood. what is the purpose of random assignment in this experiment? a, to produce treatment groups with similar characteristics b, to ensure that all people with high cholesterol have an equal chance of being selected for the study c, to increase the accuracy of the research results and prevent skewness in the data

Ascientist wants to determine the effect of a new type of gasoline. he fillsone car with normal gasoline and another identical car with the new gasoline.which is the control group? a. the new type of gasolineb. the car with the normal gasolinec. the car with the new gasolinethe amount of gasoline usedd. the amount of gasoline used