Radon is a colorless and odorless radioactive gas that can accumulate in residential homes. High levels of exposure can lead to health problems. Radon levels are measured in units of picocuries per liter (pCi / L). The recommended radon level is less than 4 pCi / L. A housing development has 105 residential homes. The homeowners association would like to estimate the average radon level in the development. Because it would be too expensive to measure every home, a random sample of 32 homes was selected to be tested, and the average radon level was found to be 1.2 pci / L. Assume from past studies the population standard deviation of radon levels in homes is 0.5 pCi / L. Complete parts a and b below. a. Construct a 90% confidence interval to estimate the average radon level in the housing development. The 90% confidence interval to estimate the average radon level is ( pci/L. pci/L) (Round to two decimal places as needed.) b. Does it appear the average radon level is below the recommendation? O A. Yes, because all the values in the confidence interval are less than 4 pci / L. O B. No, because some of the values in the confidence interval are greater than 4 pCi / L. O C. Yes, because 4 pCi /L is contained in the confidence interval. O D. No, because 4 pci / L is contained in the confidence interval.Complete the following statement. A for the mean is an interval estimate around a sample mean that provides us with a range of where the true population mean lies. O A. confidence level O B. confidence interval O C. margin of error D. significance levelAccording to a recent study, the average age of "gamers" (those that routinely play video games) is 30 years old. A random sample of 33 gamers had an average age of 32.7 years old. Assume that the population standard deviation for the age of gamers is 4.6 years. Use a 90% confidence interval to test the validity of this report and choose the one statement that is correct. O A. Because this confidence interval does not include 30 years, the report is validated. O B. Because this confidence interval does not include 30 years, the report is not validated. O C. Because this confidence interval does include 30 years, the report is validated O D. Because this confidence interval does include 30 years, the report is not validated.Medicare would like to test the hypothesis that the average monthly rate for one-bedroom assisted-living facility is equal to $3,300. A random sample of 12 assisted-living facilities had an average rate of $3,690 per month. The population is normally distributed. The standard deviation for this sample was $530. Medicare would like to set a = 0.05. Which one of the following statements is true? A. Because the p-value is less than a, we fail to reject the null hypothesis and conclude that the average monthly rate for an assisted-living facility is not equal to $3,300. O B. Because the p-value is less than a, we reject the null hypothesis and conclude that the average monthly rate for an assisted-living facility is not equal to $3,300. O C. Because the p-value is greater than a, we fail to reject the null hypothesis and cannot conclude that the average monthly rate for an assisted-living facility is not equal to $3,300. O D. Because the p-value is greater than a, we fail to reject the null hypothesis and conclude that the average monthly rate for an assisted-living facility is equal to $3,300