the two questions that have drop downs have options of known and unknown for the first and the second is t or z

A pharmaceutical company makes tranquilizers. It is assumed that the distribution for the length 01 time they last is approximately normal. Researchers in a hospital used the drug on a random sample of 9 patients. The effective period of the tranquilizer for these patients resulted in a sample mean of 2.53 hours and a sample standard deviation of 0.35 hours. (Hound answers to two decimals if needed) Given that the sample size n is U and the sample mean i is . The population standard deviation 0 is |:|. The sample standard deviation s is . We will need to use the |:|-table. The 95% condence interval for the population mean length of effective time is ( U UH U