High school students from track teams in the state participated in a training program to improve running times. Before the training the mean running time for the students to run a mile was 402 seconds with standard deviation 40 seconds Aher completing the program, the mean running time for the students to run a mile was 368 seconds with standard deviation 30 seconds Let X represent the running time of a randomly selected student before training, and let Y represent the running time of the same student after training. Which of the following is true about the dotibution of X-Y? The variables X and Y are independent, therefore, the mean is 34 seconds and the standard deviations 10 seconds 8 The variables X and Y are independent, therefore, the mean is 34 seconds and the standard deviationis 50 seconde The variables X and Y are not independent, therefore, the standard deviation is 50 seconds and the mean cannot be determined with the information given The vanabies X and Y are not independent, therefore, the meanis 34 seconds and the standard deviation cannot be determined with the information given The variables X and Y are not independent, therefore, neither the r innor the standard deviation can be determined with the information given