Question

A consumer advocate conducted a hypothesis test at the 5% significance level to determine if the mean level of impurities in a bottled water product is higher than themanufacturer’s advertised value of 20 parts per million. The advocate collected 25samples, measured the impurities, calculated a test statistic and obtained a p-value of 0.0423. Which of the following correctly states the advocate’s conclusion and reason for the conclusion?

A. Reject the null hypothesis because the p-value is smaller than the significance level of the test.

B. Fail to reject the null hypothesis because the p-value is larger than the significance level of the test.

C. Accept the null hypothesis because the p-value is smaller than the significance level of the test.

D. The conclusion cannot be determined from the information given without knowing the sample mean and standard deviation.

Answer 1

Answer:

A. Reject the null hypothesis because the p-value is smaller than the significance level of the test.

Explanation:

For the given hypothesis test, we have

P-value = 0.0423

α = 0.05

So, P-value < α

So, we reject the null hypothesis

There is sufficient evidence to conclude that the mean level of impurities in a bottled water product is higher than the manufacturer’s advertised value of 20 parts per million.