If n=15, i(x-bar)=31, and s=2, construct a confidence interval at a 80% confidence level. Assume the data came from a normally distributed population. Give your answers to one decimal place.

A researcher is interested in finding a 90% confidence interval for the mean number minutes students are concentrating on their professor during a one hour statistics lecture. The study included 117 students who averaged 36.4 minutes concentrating on their professor during the hour lecture. The standard deviation was 10.4 minutes. Round answers to 3 decimal places where possible. a. To compute the confidence interval use a distribution. b. With 90% confidence the population mean minutes of concentration is between C] and C] minutes. c. If many groups of 117 randomly selected members are studied, then a different confidence interval would be produced from each group. About C] percent of these confidence intervals will contain the true population mean minutes of concentration and about D percent will not contain the true population mean minutes of concentration. 0 Question 2 v You are interested in finding a 90% confidence interval for the average number of days of class that college students miss each year. The data below show the number of missed days for 10 randomly selected college students. Round answers to 3 decimal places where possible. "Baum a. To compute the confidence interval use a distribution. b. With 90% confidence the population mean number of days of class that college students miss is between C] and [3 days. c. If many groups of 10 randomly selected non-residential college students are surveyed, then a different confidence interval would be produced from each group. About C] percent of these confidence intervals will contain the true population mean number of missed class days and about C] percent will not contain the true population mean number of missed class days. 0 Question 4 v You are interested in finding a 98% confidence interval for the mean number of visits for physical therapy patients. The data below show the number of visits for 13 randomly selected physical therapy patients. Round answers to 3 decimal places where possible. mun-nunmm a. To compute the confidence interval use a distribution. b. With 98% confidence the population mean number of visits per physical therapy patient is between and visits. c. If many groups of 13 randomly selected physical therapy patients are studied, then a different confidence interval would be produced from each group. About percent of these confidence intervals will contain the true population mean number of visits per patient and about percent will not contain the true population mean number of visits per patient. 0 Question 5 v Assume that a sample is used to estimate a population mean p. Find the 95% confidence interval for a sample of size 763 with a mean of 40.7 and a standard deviation of 16.1. Enter your answer as a tri-linear inequality accurate to 3 decimal places.

The effectiveness of a blood-pressure drug is being investigated. An experimenter finds that, on average, the reduction in systolic blood pressure is 45.4 for a sample of size 22 and standard deviation 21.2. Estimate how much the drug will lower a typical patient's systolic blood pressure (using a 90% confidence level). Assume the data is from a normally distributed population. Enter your answer as a tri-linear inequality accurate to three decimal places.

Assume that a sample is used to estimate a population mean ,u. Find the 99% confidence interval for a sample of size 48 with a mean of 36.8 and a standard deviation of 21.3. Enter your answer as an open- interval (i.e., parentheses) accurate to 3 decimal places. The answer should be obtained without any preliminary rounding. 0 Question 8 v A botanist wishes to estimate the typical number of seeds for a certain fruit. She samples 73 specimens and counts the number of seeds in each. Use her sample results (mean = 47.2, standard deviation = 6.4) to find the 95% confidence interval for the number of seeds for the species. Enter your answer as an open-interval (i.e., parentheses) accurate to 3 decimal places. 0 Question 9 v If n=13, i:(x-bar)=40, and s=9, find the margin of error at a 80% confidence level Give your answer to two decimal places. 0 Question 10 v If n=21, :E(x-bar)=45, and s=2, construct a confidence interval at a 95% confidence level. Assume the data came from a normally distributed population. Give your answers to one decimal place.