Regression was used to estimate sales revenue ($/week) from number of customers: You are given the following linear relationship:

Estimated Sales Revenue = 30+78 Customers

Which of the following is the correct interpretation of the slope?

1. Estimate sales revenue increases by an average $108, for each extra customer.
2. Estimate sales revenue increases by an average $78, for each extra customer.
3. Estimate sales revenue increases by an average of $30, for each extra customer.
4. Estimate sales revenue decreases by an average of $30, for each extra customer.
5. Estimate sales revenue decreases by an average $78, for each extra customer.