11). A sample of 400 racing cars showed that 80 of them cost over $700,000. What is the 99% confidence interval for the true proportion of racing cars that cost over $700,000? (Be sure to show all of your work, including formulas, and round your final answer to 3 decimal places).

If n = 20, the sample mean = 250, SD = 15, SEM = 3.354, what is the confidence interval (using 95% confidence level). What percent confidence do you have that the population mean is between what two values

You are interested in constructing a 90% confidence interval for the proportion of all caterpillars that eventually become butterflies. Of the 378 randomly selected caterpillars observed, 45 lived to become butterflies. Round answers to 4 decimal places where possible. a.  With 90% confidence the proportion of all caterpillars that lived to become a butterfly is between      and   . b.  If many groups of 378 randomly selected caterpillars were observed, then a different confidence interval would be produced from each group. About         percent of these confidence intervals will contain the true population proportion of caterpillars that become butterflies and           about  percent will not contain the true population proportion.

You are interested in constructing a 95% confidence interval for the proportion of all caterpillars that eventually become butterflies. Of the 390 randomly selected caterpillars observed, 60 lived to become butterflies. Round answers to 4 decimal places where possible. a.  With 95% confidence the proportion of all caterpillars that lived to become a butterfly is between and . b.  If many groups of 390 randomly selected caterpillars were observed, then a different confidence interval would be produced from each group. About percent of these confidence intervals will contain the true population proportion of caterpillars that become butterflies and about percent will not contain the true population proportion.

If you want to be confident in your estimation of a confidence interval, you should use….