A group of students is tested on their driving ability in a research study that was done to investigate the effect of cell phone use on driving performance. A sample of 25 students drives a test...

A group of students is tested on their driving ability in a research study that was done to investigate the effect of cell phone use on driving performance. A sample of 25 students drives a test course in a driving simulator to measure their driving accuracy (based on how often they deviate from the course, miss a red light, etc.). Then, all 25 students are tested on the driving course again while holding a conversation on their cell phone with a researcher. The mean difference score in driving accuracy shows that, on average, accuracy decreases by 25% while talking on the cell phone, with a standard deviation of 15%. Does cell phone use cause a significant decrease in driving performance?