Many firms use on-the-job training to teach their employees new software. Suppose you work in the personnel department of a firm that just finished training a group of its employees in new software, and you have been requested to review the performance of one of the trainees on the final test that was given to all trainees. The mean and standard deviation of the test scores are 75 and 2, respectively, and the distribution of scores is mound-shaped and symmetric. Suppose the trainee in question received a score of 70. Compute the trainee's z-score. Z score=