This wine stinks. Sulfur compounds cause "off-odors" 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 DMS in trained wine testers is about 25 micrograms per liter of wine (µg/l). The untrained noses of consumers may be less sensitive, however. Here are the DMS odor thresholds for 10 untrained students:

31   31   43   36   23   34   32   30   20   24

Assume that the odor threshold for untrained noses is normally distributed with σ = 7 µg/l. Is there evidence that the mean threshold for untrained tasters is greater that 25µg/l?

1. The appropriate test to use is

a. T Test         

b. 1-Prop Z test          

c. Z Test          

d. Paired T test

2. The appropriate type of test to use based on the tails of the distribution

a. Left-tailed            

b. Two-tailed                

c. Right-tailed

3. The p-value of the test is closest to

a. 0.0289         

b. 0.0431        

c. 0.0134       

d. 0.0074