A regression analysis between sales (y in $ 1000) and advertising (x in dollars) resulted in the following equation: Y = 50,000 + 6x.

The above equation implies that an increase of _____.

Select one: 1. $ 6 in advertising is associated with a $ 6,000 increase in sales 2. $ 1 in advertising is associated with a $ 56,000 increase in sales 3. $ 1 in advertising is associated with a $ 6,000 increase in sales 4. $ 1 in advertising is associated with a $ 6 increase in sales