Question

7- in an experiment to test the effect of exercise on the number of times a rubber band can be stretched in 1 minutes, the dependent variable would be the
a- test subject
b- amount of exercise
c- number of stretches
d- rubber band
8-which procedure would increase the validity of the conclusions drawn from the results of an experiment?
a- increasing the number of times the activity is repeated
b- changing the temperature in the room
c- decreasing the number of students participating in the activity
d- eliminating the rest period before the resting pulse rate is taken
9- which statement best describes a controlled experiment?
it eliminates the need for dependent variables.
it shows the effect of a dependent variable on an independent variable.
it avoids the use of variables.
it tests the effect of a single independent variable.

Explanation:

Answer:

(7) C. number of stretches
(8) A. increasing the number of times the activity is repeated
(9) D. It tests the effect of a single independent variable.