Tesla, taking feedback from customers, wants to improve their infotainment touchscreen. One problem involves troubleshooting the touchscreen, which has a high failure rate after being repaired and reinstalled. The Tesla engineers suspect that standard work procedures will reduce the time required to troubleshoot the touchscreen. Time (in minutes) required for troubleshooting the touchscreen with and without the standard work procedure (i.e., some technicians use the standard work procedure and some do not use the standard work procedure) is recorded for a sample of 19 Tesla mobile technicians. Assuming that we define our time difference to repair as, u_(difference) = (Time for technicians to repair without standard work procedure) - (Time for technicians to repair with standard work procedure), the correct alternative hypothesis is