Instruction 9-4
A drug company is considering marketing a new local anaesthetic. The effective time of the anaesthetic the drug company is currently producing has a normal distribution with a mean of 7.4 minutes with a standard deviation of 1.2 minutes. The chemistry of the new anaesthetic is such that the effective time should be normal with the same standard deviation, but the mean effective time may be lower. If it is lower, the drug company will market the new anaesthetic; otherwise, it will continue to produce the older drug. A sample of size 36 results in a sample mean of 7.1. A hypothesis test will be done to help make the decision.
-Referring to Instruction 9-4,the appropriate hypotheses are

Question

Quizplus · Accepted Answer

The null hypothesis should be that the mean effective time of the new anaesthetic is not lower than that of the current anaesthetic, which is 7.4. Thus, the null hypothesis is H₀: μ ≥ 7.4. The alternative hypothesis is that the mean effective time is lower than 7.4, making the drug company market the new anaesthetic. Thus, the alternative hypothesis is H₁: μ < 7.4. The correct choice is C as it matches this setup.

Instruction 9-4 A Drug Company Is Considering Marketing a New Local Anaesthetic