Do streams with vegetated buffers (natural vegetation growthalong the stream banks) have lower total phosphorus concentrations[TP] than streams without vegetated stream buffers (and if so, bywhat magnitude)? We have randomly sampled 20 streams inthe piedmont of North Carolina (10 with buffers and ten withoutbuffers) and measured TP concentrations (mg/L)
Table 1. Summary statistics of the natural logof total phosphorus concentrations |
|
| Mean (mg/L) | Standard Deviation (mg/L) | N |
Buffered | 1.5 | 0.30 | 10 |
Not Buffered | 1.7 | 0.80 | 10 |
- Establish appropriate hypotheses for the analysis. What type oftest should you conduct?
- Calculate the appropriate test statistic and p-value for yourhypothesis test. Interpret your p-value in asentence.
c. What are the assumptions underlyingthis t-test?
