The operations manager of a plant that manufactures tires wishes to compare the actual inner diameter of two grades of tires, ea
ch 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, ranked from smallest to largest, are as follows: Grade X
568 570 575 578 584
Grade Y
573 574 575 577 578
a. For each of the two grades of tires, compute the mean, median, and mode.
b. Compute and Interpret S
c. Which grade of tire is providing better quality? Explain.
d. What would be the effect on your answers in (a) if the last value for grade Y were
given that 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, ranked from smallest to largest, are as follows:
For this case, the first thing we must do is define variables: x: number of quarters y: number of nickels We now write the system of equations: x + y = 68 0.25x + 0.05y = 13.40 Solving the system we have: x = 50 y = 18 Answer: they have: quarters = 50 nickels = 18
