Hi, I need help with these questions. Thank you!

You measure 33 textbooks' weights, and find they have a mean weight of 51 ounces. Assume the population standard deviation is 12.9 ounces. Based on this, construct a 99% confidence interval for the true population mean textbook weight. Round your critical value to 2 decimal places. Round answers to at least 4 decimal places. < Select an answer v < If n=21 , and =15, construct a confidence interval at a 80% confidence level. Assume the data came from a normally distributed population. Round your critical value to two decimal places. Give your answers to one decimal place. You measure 28 textbooks' weights, and find they have a mean weight of 50 ounces. Assume the population standard deviation is 3.8 ounces. Based on this, construct a 95% confidence interval for the true population mean textbook weight. Round your critical value to two decimal places. Give your answers as decimals, to two places. You want to obtain a sample to estimate a population mean. Based on previous evidence, you believe the population standard deviation is approximately c 42.9. You would like to be 99% confident that your estimate is within 2 of the true population mean. How large of a sample size is required? Use a critical value rounded to two decimal places. Give your answer in whole people. Make sure you use the correct rounding rule for samples size. ou Intend to estimate a population mean with a confidence interval. You do not know the population standard deviation, but you believe the population to have a normal distribution. Your sample size is 4. While it is an uncommon confidence level, find the critical value that corresponds to a confidence level of 82%. (If you can not find the appropriate value on your table, please use the InvTfunction in Google sheets. Report answer accurate to three decimal places with appropriate rounding.) tan =