A scientist is investigating the cause of an unusual color in the lake water of a specific location. Four residents of the locat
ion responded to questions asked by the scientist. The chart below shows their responses. Questions Resident 1's answer Resident 2's answer Resident 3's answer Resident 4's answer Do you work at the coal mine near the lake? Yes No No Yes Do you use the lake water for daily chores? Yes Yes No Yes Is your family income affected by the presence of the coal mine near the lake? No Yes No Yes Which resident's information would the scientist most likely record to get valid results? Resident 1 Resident 2 Resident 3 Resident 4
The answer depends on someone who would most impartial, meaning not having an opinion that could change because of money (question 3), would need to have some knowledge of the lake (question 2) and would not alter results to avoid implicating the coal mine (question 1). The best choice is 1 because this person uses the water, but would not be affected economically by discussing the lake and the coal mine. Number 3 is the second best choice because they have answered no to all three questions. The reason Number 3 is not the best choice is because they do not regularly use the water, unlike Number 1.
Fish will eat tadpoles if they can get to them. The only way to stop them would be to give the tadpoles a space that the fish can't get to, like a shallow area with a barrier (plastic mesh would work but make sure the fish can't get caught in it) or lots of plants, or make a separate wildlife pond.
