Sulfur compounds cause "offodors" in wine, so winemakers want to know the odor threshold, the lowest concentration of a compound that the human nose can detect. The odor threshold for dimethyl sulfide (DMS) in trained wine tasters is about 25 micrograms per liter of wine (g/L ). The untrained noses of consumers may be less sensitive, however. The DMS odor thresholds for 10 untrained students are given. 30 30 42 35 22 33 31 29 19 23 What is the average (mean) DMS odor threshold, , for all untrained people? PLAN: Using the fourstep process, give a 95% confidence interval for the mean DMS odor threshold among all students. SOLVE: We have assumed that we have a random sample and that the population from which we are sampling is Normal. Find . (Enter your answer rounded to one decimal place.) = x Find the standard deviation, , of the sampling distribution of . (Enter your answer rounded to four decimal places.)