The operations manager of a plant that manufactures tires wishes to compare the actual inner diameter of two grades of tires, each of which has a nominal value of 575 millimeters. A sample of five tires of each grade is selected, and the results representing the inner diameters of the tires, ordered from smallest to largest, are as follows: Grade X: 568, 570, 575, 578, 584
Grade Y: 573, 574, 575, 577, 578
a. Compute the mean, median, and standard deviation for each grade of tire.
b. What would be the effect on your answers in (a) and (b) if the last value for grade Y was 588 instead of 578? Explain.
c. Which grade of tire is providing better quality? Explain.