When potential workers apply for a job that requires extensive manual assembly of small intricate parts, they are initially given three different tests to measure their manual dexterity. the ones who are hired are then periodically given a performance rating on a 0 to 100 scale that combines their speed and accuracy in performing the required assembly operations. the file p11_44.xlsx lists the test scores and performance ratings for a randomly selected group of employees. it also lists their seniority (months with the company) at the time of the performance rating.