Statistical Inferences Answers

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?

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 .

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?

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?

Which of the following statements is correct?

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?

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?.

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?

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?

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