A student wants to investigate what concentration of a salt solution is most effective in preventing the growth of bacteria. The agriscience student prepares five dishes of agar (a gelatin-like substance used to cultivate living material). The student spreads the solutions of different salt concentrations on four dishes leaving one dish untouched. Then they introduce bacteria on all the dishes and observe the dishes for the amount of bacterial growth .
1) What is the control /constant?
2) What is the dependent variable? 3) What is the independent variable?
4) Are the variables qualitative or quantitative? Why
5) Identity possible sources of unavoidable experimental error
