The EPA has stipulated that the Pollution Standard Index (PSI)for clean air standards is to average no more than 100.A random sample of 9 days for the city of Acorn showed PSI readings of 144,85,90,120,150,105,93,130,and 115.The EPA wants to test to determine if Acorn's air is dirtier than the stipulated clean air standards.Assume the population of PSI readings is highly nonnormal and state the null hypothesis. A)H₀: M_d ≥ 100 B)H₀: M_d ≤ 100 C)H₀: M_d ≠ 100 D)H₀: M_d 100

Question

The EPA has stipulated that the Pollution Standard Index (PSI)for clean air standards is to average no more than 100.A random sample of 9 days for the city of Acorn showed PSI readings of 144,85,90,120,150,105,93,130,and 115.The EPA wants to test to determine if Acorn's air is dirtier than the stipulated clean air standards.Assume the population of PSI readings is highly nonnormal and state the null hypothesis. A)H₀: M_d ≥ 100 B)H₀: M_d ≤ 100 C)H₀: M_d ≠ 100 D)H₀: M_d > 100

Quizplus · Accepted Answer

The null hypothesis should state that the population mean (MS) of PSI readings for Acorn is not greater than 100, as that is what the EPA stipulates as the maximum average PSI. Therefore, the correct null hypothesis is H₀: M_d ≤ 100. Choice A states the alternative hypothesis incorrectly, as it should state M_d < 100 instead of ≥ 100. Choice C is also incorrect, as the null hypothesis should be a statement about the population mean, not whether it is equal to a certain value. Choice D is incorrect because it states the alternative hypothesis instead of the null hypothesis.

The EPA Has Stipulated That the Pollution Standard Index (PSI)for