8 Questions
| Total Attempts: 49

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Questions and Answers

- 1.
- 2.Suppose a consumer advocacy group would like to conduct a survey to find the proportion p of consumers who bought the newest generation of an MP3 player were happy with their purchase. They take a random sample of 1000 consumers who recently purchased this MP3 player and find that 400 were happy with their purchase. Find a 95% confidence interval for p. What z-score should you use for this confidence level?
- 3.
- 4.Suppose a consumer advocacy group would like to conduct a survey to find the proportion p of consumers who bought the newest generation of an MP3 player were happy with their purchase. They take a random sample of 1000 consumers who recently purchased this MP3 player and find that 400 were happy with their purchase.Finally,
**find the 95% confidence interval**for p. (Do not use spaces in your answer) - 5.
- 6.
- 7.The operations manager of a large production plant would like to estimate the mean amount of time a worker takes to assemble a new electronic component. Assume that the standard deviation of this assembly time is 3.6 minutes. After observing 120 workers assembling similar devices, the manager noticed that their average time was 16.2 minutes. Construct a 90% confidence interval for the mean assembly time. What is the margin of error, E (rounded to 2 decimal places)?
- 8.The operations manager of a large production plant would like to estimate the mean amount of time a worker takes to assemble a new electronic component. Assume that the standard deviation of this assembly time is 3.6 minutes. After observing 120 workers assembling similar devices, the manager noticed that their average time was 16.2 minutes. Construct a 90% confidence interval for the mean assembly time.