The average life expectancy of tires produced by Whitney Tire Company has been 40,000 miles. Management believes that due to a new production process, the life expectancy of its tires has increased. In order to test the validity of this belief, the correct set of hypotheses is _____. A) H0: μ 40,000 C) H0: μ 40,000 H_a: μ ≤ 40,000 D) H0: μ ≥ 40,000 H_a: μ

Question

The average life expectancy of tires produced by Whitney Tire Company has been 40,000 miles. Management believes that due to a new production process, the life expectancy of its tires has increased. In order to test the validity of this belief, the correct set of hypotheses is _____. A) H0: μ < 40,000 H_a: μ ≥ 40,000 B) H0: μ ≤ 40,000 H_a: μ > 40,000 C) H0: μ > 40,000 H_a: μ ≤ 40,000 D) H0: μ ≥ 40,000 H_a: μ < 40,000

Quizplus · Accepted Answer

The null hypothesis (H0) should always have the equality sign and represent the belief that no change or effect has occurred. Since the company believes that the new production process has increased the life expectancy of tires, the alternative hypothesis (H1) should reflect this by having the inequality sign and stating that the population mean (μ) is greater than the previous average of 40,000 miles. Therefore, the correct set of hypotheses is H0: μ ≤ 40,000 vs. H1: μ > 40,000. Choice B correctly represents these hypotheses.

The Average Life Expectancy of Tires Produced by Whitney Tire