Class A and Class B have the same mean mark, but Class A has a much larger standard deviation. What does this mean?
Answer and explanation
Correct answer: D. Class A's marks are spread further from the mean than Class B's
- Step 1: The mean is the same, so it tells nothing about the difference. Step 2. Standard deviation measures dispersion; a larger value means the marks are more spread out. Answer: Class A's marks are spread further from the mean. Why not the others: Both averages are equal, and standard deviation says nothing about class size or identical marks.
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