Full question:
In an experiment, Dr. Travis examined the effects of calcium intake on osteoporosis, a condition that causes an increased risk of bone fractures. The amount of calcium is_______ variable. The risk of bone fractures_________ .
1. - A reliable
- an independent
- a dependent
2. - can be changed by the participants
- can be changed by the researcher
- could change with calcium
Answer:
1. an independent
2. could change with calcium
Explanation:
In the experiment conducted by Dr. Travis, amount of calcium is an independent variable. This is because, Dr. Travis wants to study the effect of different concentration of calcium in healing osteoporosis (a disease that causes reduced bone mass). So, the choice of calcium concentration is purely in Dr. Travis hand.
On ther other hand, upon application, the risk of bone fracture would be driven by the amount of calcium intake after application. Dr. Travis would not know before the experiment that which concentration of calcium was best in healing. So, the risk of bone fracture after the application is depending upon the concentration of calcium and would change accordingly.
