A professional bowler wanted to gather data about the cost of local bowling leagues in the area. After collecting and plotting the data, it was determined that the average bowling league consists of a one-time registration fee and a monthly fee modeled by the equation ŷ = 19x + 20.

Identify and interpret the slope in this scenario.

The slope is 19. Starting at $20, the cost will decrease by $19 per month.
The slope is 19. Starting at $20, the cost will increase by $19 per month.
The slope is 20. Starting at $19, the cost will increase by $20 per month.
The slope is 20. Starting at $19, the cost will decrease by $20 per month.