Manufacturing and Product Development
A major cause of injuries in highway work zones is weak construction barriers. One federal government road-barrier specification involves the velocity of a front-seat passenger immediately following impact. This impact velocity must be less than 12 m/s. TSS GmbH, a German company, has just developed a new highimpact road barrier with special absorbing material. In controlled tests the impact velocity was measured for 12 randomly selected crashes. The sample mean was 11.85 m/s. Assume the distribution of impact velocities is normal and σ = 0.26.
a. Conduct a hypothesis test to determine whether there is sufficient evidence to suggest the true mean impact velocity is less than 12 m/s. Use a = 0.05.
b. What is your conclusion if a = 0.01?