A purchasing agent for a trucking company is shopping for replacement tires for their trucks from two suppliers. The suppliers' prices are the same. However, Supplier A's tires have an average life of 100,000 km with a standard deviation of 10,000 km. Supplier B's tires have an average life of 100,000 km with a standard deviation of 2,000 km. Which of the following statements is true?
A) The two distributions of tire life are the same
B) On average, Supplier A's tires have a longer life then Supplier B's tires
C) The life of Supplier B's tire is more predictable than the life of Supplier A's tires
D) The dispersion of Supplier A's tire life is less than the dispersion of Supplier B's tire life
E) The life of Supplier A's tire is more predictable than the life of Supplier B's tires

Question

Quizplus · Accepted Answer

The standard deviation is a measure of the dispersion or variability in a dataset. A smaller standard deviation, like that of Supplier B's tires (2,000 km), indicates that the tire life is more closely clustered around the mean (100,000 km), making it more predictable than Supplier A's tires, which have a larger standard deviation (10,000 km) indicating a wider spread of tire life around the same mean.

A Purchasing Agent for a Trucking Company Is Shopping for Replacement