Suppose you're trying to measure the Selenium toxicity in your tap water, and obtain the following values for each day:
| day | selenium |
|---|---|
| 1 | 0.051 |
| 2 | 0.0505 |
| 3 | 0.049 |
| 4 | 0.0516 |
| 5 | 0.052 |
| 6 | 0.0508 |
| 7 | 0.0506 |
The maxiumum level for safe drinking water is 0.05 mg/L -- using this as your alpha, does the selenium tap level exceed the legal limit? Hint: you can use a t-test here.