Question

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Explanation:

🆕 New Concept Discovered: Experimental Design: Control vs. Treatment Groups
A baseline for comparison

Step 1: Understand the goal of the study

The study is designed to test a specific claim: that combining vitamin C with vitamin E is more effective at preventing the flu than taking vitamin C alone.

Step 2: Identify the roles of the groups

To evaluate if an added variable (vitamin E) has an effect compared to a baseline, we need:

• Treatment groups: The groups receiving the active intervention being tested (vitamin C combined with different doses of vitamin E).
• Group 2: \( 600\text{ mg} \) Vitamin C + \( 200\text{ IU} \) Vitamin E
• Group 3: \( 600\text{ mg} \) Vitamin C + \( 400\text{ IU} \) Vitamin E
• Control group: The baseline group used for comparison that does not receive the active new treatment (vitamin E) but receives the standard or comparison treatment (vitamin C alone).
• Group 1: \( 310 \) subjects taking \( 600\text{ mg} \) of vitamin C alone.

Step 3: Match with the options

The first group of 310 subjects taking vitamin C alone serves as the control group because it provides the baseline rate of flu incidence to which the vitamin E combination groups are compared.

Answer:

the first group of 310 taking vitamin C alone