a linear regression model used to estimate the demand function for coca cola for 60 person yielded the following result

Qd= 10425-2910px+.028A+11100pop

SE (1010)(.004)(3542)

R sequare = .7

Where QD = quantity demand of coca cola px = price of cola A = advertizing in dollar pop = percantage of paLESTINE POPULATION OVER 15 YEAR

1- DETERMINE THE POINT PRICE ELASTICITY AND ADVERTISING FOR PRICE OF 5 $ WHEN a= 1000000 AND POP = .05

2- WHAT IS THE CHANGE IN qD RESULTS FROM 5000 $ INCREASE IN ADVERTISING

3- WHT IS THE PERCENT CHANGE IN qd RESULT FROM 2% INCREASE IN POP ?

4- TEST IF THERE SIGNIFICANT RELATIONSHIP BETWEEN EACH INDEPENDENT VARIABLE and QD at alpha = .05

5- test the goodness of fit ( the overall level of significant at alpha = .05

what is the interpretation of R sequare