1.73. The widths of copper lines in printed circuit boards must be close to a design value. Three manufacturers were asked to prepare circuit boards with copper lines that are 0.500 m (micrometers) wide (1 m = 1 x 106 m). Each manufacturer's quality control department reported the following line widths on five sample circuit boards (given in micrometers): Manufacturer 1 0.512 0.508 0.516 0.504 0.513 1.74 Manufacturer 2 0.514 0.513 0.514 0.514 0.512 Dishata Manufacturer 3 0.500 I 0.501 0.502 0.502 0.501 a. What is the mean and standard deviation of the data provided by each manufacturer? b. For which of the three sets of data does the 95% confidence interval include 0.500 m? c. Which of the data sets fit the description "precise and accurate," and which is "precise but not accurate"? -01