Aj Department Stores Math 533

Math 533

August 22, 2014

AJ Davis Department Store

Part C

Generate a Scatterplot for credit vs Size including the best fit line interpret.

The scatterplot graph above with the best fit line shows that there is a positive relationships between the credit balance and the size. When size increases the credit balance increases and vice versa.

2. Determine the equation of the best fit line which describes the relationship between credit balance and size.

The equation is;

Credit Balance ($) = 2582 + 404 Size

Predictor Coef SE Coef T P

Constant 2581.9 195.3 13.22 0.000

Size 404.13 51.00 7.92 0.000

S = 620.793 R-Sq = 56.7% R-Sq (adj) = 55.8%

Analysis of Variance

Source DF SS MS F P

Regression 1 24200717 24200717 62.80 0.000

Residual Error 48 18498431 385384

Total 49 42699149

Predicted Values for New Observations

New Obs Fit SE Fit 95% CI 95% PI

1 4602.6 119.2 (4363.0, 4842.2) (3331.6, 5873.6)

Values of Predictors for New Observations

New Obs Size

1 5.00.

3. Determine the coefficient if correlation. The coefficient of correlation is or “r’ is the range between -1 and +1 with 0 being the middle. The more close to one or the other the stronger the correlation is to between the two variables. For this coefficient correlation r= 0.752843 therefore the variables are more closely to the +1 meaning that there is a positive strong relationship between the variables credit balance and size.

4.Determine the coefficient of determination. Interpret. The regression model is 56.7% and the coefficient of determination is 0.56677.

5.Test the utility of this regression...