A Tree Farmer Hires a Botanist to Evaluate a Blight

A tree farmer hires a botanist to evaluate a blight that seems to be affecting his trees. The trees are planted in horizontal rows
on a hill and the blight seems to be a bigger problem near the bottom of the hill. The farmer wants to know the extent of the
damage to the trees. Since the trees must be destroyed to examine them, the botanist doesn't have time to examine all the
trees, so she will select a sample. Several plans for choosing the sample are proposed.
a. Randomly select three trees from each horizontal row.
b. Lay out a grid on a map of the hill. Randomly select eight squares from the grid, and check all trees in those squares.
c. Randomly pick a number from 1 to 30. Start at the tree at that position in the first row, then go to every 30th tree after that.
d. Check the ten trees closest to the parking lot where the botanist parks her car.
-Describe the kind of bias that might be present if the administration decides that instead of
subjecting people to random testing they'll just…
a. drop grains of rice on the aerial photo of the hill and inspect the trees that had rice land
on them.
b. ask the farmer to choose which trees he would like tested.