Discuss the below:
Q1. (a) What is the meaning of the term "null hypothesis".
(b) How do you know when to perform a "left-tailed" test in a hypothesis-testing situation versus a "right-tailed" or "two-tailed" test?
Q2. A hypothesis test is used to test a claim. You get -1.47 as your test statistic and had -1.96 as your critical value in a left-tailed test. Which of the following is the correct decision statement for the test?
A. Reject the null hypothesis
B. Claim the null hypothesis is valid
C. Fail to reject the null hypothesis
D. Claim the alternative hypothesis is true
Q3. A hypothesis test is used to test a claim. You get a p-value of 0.03 on a test with a significance level of 0.05. Which of the following is the correct decision statement for the test?
A. Reject the null hypothesis
B. Claim the null hypothesis is valid
C. Fail to reject the null hypothesis
D. Claim the alternative hypothesis is true
Q4. Suppose a company that produces a weight loss product makes the claim that people who use its product as directed will lose more weight than people who use other weight loss products. In words, describe the Type I error you could make if you test this claim through a formal hypothesis test on collected data.