Safelite guaranteed an $11 hourly wage when it rolled out performance pay, so it paid installers $20 per windshield or $11 per hour, whichever was greater. How many windshields must a worker install in an 8-hour day for performance pay to equal the $11 hourly wage? Workers installed 2.5 windshields per day before performance pay. Did it take a little or a lot of extra effort to reach the "incentive zone"?