Statistical Inferences Answers

Which of the following z-values, standard deviations, and sample sizes produce a margin of error of 0.95?

A simple random sample is drawn from a normally distributed population. The value of which of the following will not be known for certain but can be inferred?

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?

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?

When finding the margin of error for the mean of a normally distributed population from a sample, what is the critical probability, assuming a confidence level of 86%?

All else being equal, if you cut the sample size in half, how does this affect the margin of error when using the sample to make a statistical inference about the mean of the normally distributed population from which it was drawn?.

The number of sit-ups that all tenth-grade girls can do in 5 minutes is normally distributed. Beth surveyed 20 of her fellow intramural tennis players, all tenth-grade girls, and determined the mean number of sit-ups they could do. Can she make an inference about the population mean for all tenth-grade girls based on the sample?

Dawn and Pablo are members of a normally distributed population that is being sampled. If the chance of Dawn being included in the sample is 0.05%, what must the chance of Pablo being included in the sample be in order to be able to make inferences about the population based on the sample?

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 .

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 .