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Question:
The 80% confidence interval for the population standard deviation is 7.7<o<13.3. Which of the following could be the interval of we changed the confidence level to 90%.

A. (7.9,13.1)
B. (8.2,12.1)
C. (6.85,14.77)

dad2021-04-08T04:55:24Z

Higher confidence → Wider confidence interval.
Therefore C. (6.85,14.77)