Question

A large retail store wants to estimate the average amount of time (μμ) its customers wait in line during checkout. In a simple random sample of 46 customers, the average wait time was 231.3 seconds. The wait times in the sample had a standard deviation of 34.29 seconds.In each question below, give answers to at least three decimal places.

1. Find a 90% confidence interval for μμ, using the above sample data:

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   Equation Editor <μ<<μ<

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   Equation Editor
2. Find a 95% confidence interval for μμ, using the above sample data:

   equation editor

   Equation Editor <μ<<μ<

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   Equation Editor
3. Find a 99% confidence interval for μμ, using the above sample data:

   equation editor

   Equation Editor <μ<<μ<

Among recent college graduates who had at least one student loan during college, we took a Simple Random Sample of size 18. The average monthly student loan payment for those in the sample was $363.07; the (sample) standard deviation was $49.05.

Part 1:

Use the sample data to find a 99% confidence interval for the average monthly student loan payment among all recent college graduates who had at least one student loan during college.Round all answers to the nearest cent (two decimal places).The margin of error for this confidence interval is: $

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The 99% confidence interval is:$

<μ<<μ< $

Answer 1