High school students from track teams in the state participated in a training program to improve running times. Before the training, the mea

Question

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. After 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 distribution of X-Y?

a. The variables X and Y are independent, therefore, the meanis 34 seconds and the standard deviation is 10 seconds.
b. The v ales X and Y are independent therefore, the meanis 34 seconds and the standard deviation is 50 seconds
c. 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.
d. The variables and are not independent, therefore, the meanis 3 seconds and the standard deviation cannot be determined with the information given
e. The variables X and Y We not independent, therefore, neither the mean nor the standard deviation can be determined with the informantion given.

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Verity 2 months 2021-07-31T03:23:11+00:00 1 Answers 3 views 0

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    2021-07-31T03:24:39+00:00

    Answer:

    D

    Step-by-step explanation:

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