Leo placed two circles of paper and a petri dish (something used for bacteria ) one circle of paper was soaked in penicillin the other had nothing on it. he poured a liquid filled with bacteria into the petri dish both circles of paper were placed in the petri dish about 3 cm apart at the end of the experiment a circle with a radius of 2 centimeters formed around the circle of paper soaked in penicillin there where no bacteria growing in the two centimeter circle nothing had occurred around the other circle of paper the victoria were going well. a. what was the dependant variable ? b. what was the dependant variable ? c. what was the control group? d. was there a controlled variable? e. if yes, explain

The independent variable is the variable in the experiment which can be manipulated or changed in an experiment, the effect of such change can be observed on the dependent variable. The dependent variable is the one which cannot be manipulated in the experiment and changes occurring in the dependent variable is because of affect of the changes in the independent variable. The control group is the group of the experimental study that does not receive treatment by the researchers. A control variable is the variable which remains constant and does not change in the experiment.

a. The dependent variable is the growth of bacteria.

b. The independent variable is the penicillin.

c. The control group is the paper circle which is not treated with penicillin.

d. The controlled variable is the paper not treated with penicillin.

e. The growth of bacteria is the dependent variable because it dependents upon the absence or presence of the penicillin. In the paper circle that lacks the penicillin shows the growth of bacteria and the paper circle socked with penicillin the growth of bacteria does not occur because it is an antibiotic  which kills bacteria.

The penicillin is the independent variable because the effect of this can be observed on bacterial growth.

pythagoras' theorem

square root (-5^2+9^2)

square root (25+81)

square root (106)

angle is tan^-1(9/5)

neg x, pos y