Question

The manufacturer of a certain engine treatment claims that if you add their product to your​ engine, it will be protected from excessive wear. An infomercial claims that a woman drove 4 hours without​ oil, thanks to the engine treatment. A magazine tested engines in which they added the treatment to the motor​ oil, ran the​ engines, drained the​ oil, and then determined the time until the engines seized.

​(a) Determine the null and alternative hypotheses that the magazine will test.

H₀​: μ=4. H₁<4.

I'm a bit confused here as the both hypotheses here state the μ of an engine, but can't here be the σ of an engine or p of an engine? Also, using the information obtained from a woman is more likely a sample mean, rather than a population mean?

In addition, how do we know H₁<4 yet the magazine only said that the time is determined until the engines seized? Thanks a lot for answering all my questions?

Answer 1