Statistical Inferences Answers

The times it took for 35 loggerhead sea turtle eggs to hatch in a simple random sample are normally distributed, with a mean of 50 days and a standard deviation of 2 days. Assuming a 95% confidence level (95% confidence level = z-score of 1.96), what is the margin of error for the population mean?Remember, the margin of error, ME, can be determined using the formula .

Which of the following statements is correct?

A simple random sample of 90 is drawn from a normally distributed population, and the mean is found to be 138, with a standard deviation of 34. What is the 90% confidence interval for the population mean? Use the table below to help you answer the question.Confidence Level90%95%99%z*-score1.6451.962.58Remember, the margin of error, ME, can be determined using the formula .

What is the z-score with a confidence level of 95% when finding the margin of error for the mean of a normally distributed population from a sample?

Suppose the mean of a normally distributed population is 300, and 200 simple random samples are drawn from the population. At a 68% confidence level, (one standard deviation from the mean), about how many of the samples’ confidence intervals would you expect to contain the population mean?

Jason and Yolanda both drew a simple random sample from a non-normally distributed population of 25,000. Jason’s sample consisted of 0.24% of the population, while Yolanda’s sample consisted of 0.32% of the population. Whose sample can be used to make inferences about the population?

A simple random sample is drawn from a normally distributed population, and when making a statistical inference about the population mean, the margin of error is found to be 5.9 at a 95% level of confidence. If the mean of the sample is 18.7, what is the 95% confidence interval for the population mean?

A simple random sample of 85 is drawn from a normally distributed population, and the mean is found to be 146, with a standard deviation of 34. Which of the following values is outside the 99% confidence interval for the population mean? Use the table below to help you answer the question.Confidence Level90%95%99%z*-score1.6451.962.58Remember, the margin of error, ME, can be determined using the formula .

Which of the following conditions must be met in order to make a statistical inference about a population based on a sample if the sample does not come from a normally distributed population?

A simple random sample of 60 is drawn from a normally distributed population, and the mean is found to be 28, with a standard deviation of 5. Which of the following values is within the 95% confidence interval (z-score = 1.96) for the population mean?Remember, the margin of error, ME, can be determined using the formula .