est the hypothesis (using z-test) of each of the following situations. Show complete steps. 2. Industrial pollution often makes water supplies acidic (pH < 7) or basic (pH > 7). An industrial company claims that the mean pH level of the water in a nearby water is 7, so it is neutral. You, as an environmentalist, randomly select 19 water samples and measure the pH of each. The sample mean and standard deviation are 6.9 and 0.24, respectively. Assume the population of pH leves in all possible water samples is normally disrtibuted. Is there enough evidence to reject the company's claim at the 5% significance level? At the 10% level? (follow these steps) Step1: Formulate the null and the alternative hypothesis. Step2: Specify the level of significance and decide whether a one-tailed test (left or right-tailed) or a two-tailed test shall be used. Step3: Decide the test statistic to be used such as (z-test, t-test, chi-squared, or F). Find the critical or tabular value. Step4: Compute for the value of the test statistic using the data from the population and the sample/s. Step5: Make a decision. a. If the computed value of the test statistic is greater than the critical or tabular value, reject the null hypothesis and accept the alternative hypothesis. b. If the computed value of the test statistic is less than the critical or tabular value, accept the null hypothesis and reject the alternative hypothesis. Step 6: State the conclusion.
Test the hypothesis (using z-test) of each of the following situations. Show complete steps.
2. Industrial pollution often makes water supplies acidic (pH < 7) or basic (pH > 7). An industrial company claims that the mean pH level of the water in a nearby water is 7, so it is neutral. You, as an environmentalist, randomly select 19 water samples and measure the pH of each. The sample mean and standard deviation are 6.9 and 0.24, respectively. Assume the population of pH leves in all possible water samples is normally disrtibuted. Is there enough evidence to reject the company's claim at the 5% significance level? At the 10% level?
(follow these steps)
Step1: Formulate the null and the alternative hypothesis.
Step2: Specify the level of significance and decide whether a one-tailed test (left or right-tailed) or a two-tailed test shall be used.
Step3: Decide the test statistic to be used such as (z-test, t-test, chi-squared, or F). Find the critical or tabular value.
Step4: Compute for the value of the test statistic using the data from the population and the sample/s.
Step5: Make a decision.
a. If the computed value of the test statistic is greater than the critical or tabular value, reject the null hypothesis and accept the alternative hypothesis.
b. If the computed value of the test statistic is less than the critical or tabular value, accept the null hypothesis and reject the alternative hypothesis.
Step 6: State the conclusion.
Trending now
This is a popular solution!
Step by step
Solved in 2 steps with 2 images
