Question:

Answer: Not correct because this implies certainty.

Question:

Answer: Not correct because different samples will give different results.

Question:

Answer: Not correct because this is about the population proportion, not the sample proportion of different samples.

Question:

Answer: Not correct because we know that 88% of the orders arrive on time with a margin of error of 6%.

Question:

Answer: Not correct because the parameter is talking about the interval, not the days.

Question: Several factors are involved in the creation of a confidence interval. Among them are the sample size, the level of confidence, and the margin of error. Is this statement true?

For a given sample size, higher confidence means smaller margin of error.

Answer: False.

Question: Several factors are involved in the creation of a confidence interval. Among them are the sample size, the level of confidence, and the margin of error. Is this statement true?

For a specified confidence level, larger samples provide smaller margins of error.

Answer: True.

Question: Several factors are involved in the creation of a confidence interval. Among them are the sample size, the level of confidence, and the margin of error. Is this statement true?

For a fixed margin of error, larger samples provide greater confidence.

Answer: True.

Question: Several factors are involved in the creation of a confidence interval. Among them are the sample size, the level of confidence, and the margin of error. Is this statement true?

For a given confidence level, halving the margin of error requires a sample twice as large.

Answer: False.

Question: What fraction of cars made in Japan? The computer output below summarizes the results of a random sample of 50 autos. Explain carefully what it tells you.

z-interval for proportion

With 90.00% confidence

0.29938661< P(Japan) < 0.46984416

Answer: On the basis of this sample, we are 90 confident that the proportion of Japanese cars is between 29.9% and 47.0%.