need help please!!!!!!!!!

there are many factors to consider for the effect on population growth like, social status, financial stability, in and out of monetary, education, politics, religion, and environment. pertaining to how to calculate r square, what do you mean linear or multi linear regression? the model is good when then r square is at least x, where x is fraction greater than 50%... when less than or equal to 0.5 then it depends... like if the deflation of the adjusted r square is 25% then what is the best value for r square? then the answer will that depends... hope this will help even a little...