The correlation Coefficient is used to show the strength and type of relationship which exists between the dependent and independent variable. The correlation Coefficient value ranges from - 1, to 1. With values closer to either - 1 or 1 depicting a strong relationship while those closer to 0 represents weak relationship. And correlation Coefficient of 0 indicates that no relationship exiata at all. Depending in the sign, that is positive or negative, positive sign means positive relationship while a negative sign represents a negative association. Positive association is interpreted as, for every increase in A, Variable B also increase and vice versa. For negative association, When A increases, B decreases and vice versa
You multiply 30 dollars by 0.85 (1-0.15, with the 0.15 being for the 15 percent off). Which gets you to $25.50, and you then multiply it by 1.082 (the 1.082 being the tax, and the .082 part equating to the 8.2% tax percentage).