An engineer wants to determine the bias in pH meter. She employs the meter to determine the pH in 12 neutral substances (pH=7.0) and obtains following data: 7.04 7.31 7.04 7.01 6.97 7.00 7.00 6.99 7.04 6.97 7.27 7.04 Is there sufficient evidence to support claim that the pH meter isn't correctly calibrated at the alpha= .05 level of significance?
a. Determine the sample mean (4 decimals) ____
b. Determine the sample standard deviation (4 decimal places)__ (calculator acceptable)
c. Describe the null and the alternate hypotheses. Ho: ____Ha:_______
d. Explain the critical value(s) for this test. ____
e. Determine the test statistic. ______
f. Approximate the p-value for this test.____
g. Find the appropriate Confidence Interval for this problem. (______, ______)
h. State your conclusion in the context of this problem.