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The share of amount which is established by Mike is independent variable because it is unaffected by the number of minutes which are talked by Mike. The number of minutes which are talked by Mike is dependent variable because it depends on the share of amount which is established by Mike.![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")
The share of amount which is established by Mike is independent variable and the number of minutes which are talked by Mike is dependent variable.