A variable is normally distributed with mean 50 and standard deviation 15. Approximately what percentage of values lie between 35 and 65?
Answer and explanation
Correct answer: C. 68%
- Step 1: The interval is within 1 standard deviation of the mean, which holds about 68% of the values (the 68-95-99.7 rule).
Answer
68%.
Why not the others: 95%: uses the wrong standard deviation band. 50%: gives half the distribution. 99.7%: uses three standard deviations.
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