Question

Local government is worried that runoff from a corporate farm has caused water in a nearby stream to become acidic. The pH is used to measure the acidity/alkalinity of a substance. Pure water, for instance, has a pH of 7, and smaller pH values indicate acidity, while larger values indicate alkalinity. A contractor is hired to test the hypothesis that the water is significantly acidic.

Use this information to answer questions 3 and 4.

3) Select the correct null and alternative hypotheses.

Select one or more:

H₀: μ = 0

H₀: μ = 7

H₀: μ≠ 7

H₀: μ = 14

H_A: μ ≠ 7

H_A: μ < 7

H_A: μ > 0

H_A: μ<14

4) The contractor took 28 water samples and found an average pH of 6.5 with a sample standard deviation of 1.3. What is the test statistic for this sample?

Give your answer to 2 decimal places. For help on how to input a numeric answer, please see “Instructions for inputting a numeric response.”

Answer 1