# Construct a 98.5% Confidence interval

I need some guidance for the following question:

A survey was conducted to determine the percentage of students at a post-secondary institution who prefer the new alpha-grading system. The responses from a random sample of 30 students are shown below.

Yes No Yes Yes No Yes

No Yes Yes No Yes No

Yes No Yes No Yes Yes

Yes Yes No Yes No No

No Yes Yes No Yes Yes

Construct a 98.5% Confidence interval for the population proportion who prefer the new alpha-grading system.

Note: Express the Confidence interval to 4 decimal places of accuracy.

https://brainmass.com/statistics/confidence-interval/confidence-interval-alpha-grading-system-370136

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This solution contains a detailed explanation of how to calculate a 98.5% confidence interval.

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