Phosphorous is a chemical that is found in many household
cleaning products. Unfortunately, phosphorous also finds its way
into surface water, where it can harm fish, plants, and other
wildlife. Two methods of phosphorous reduction are being studied.
At a random sample of 7 locations, both methods were used and the
total phosphorous reduction (mg/L) was recorded. Note: For
degrees of freedom d.f. not in the Student's t table, use
the closest d.f. that is smaller. In some situations, this...