Answer to Question #344588 in Statistics and Probability for Ayen

Question

Given the following situations, write A, if it is two-tailed, B if one-tailed (left-tailed), and C if one-tailed (right-tailed). (10 points)

1. A mother wants to prove that listening to classical music improves children's thinking process.

2. The principal of a certain school claims that the dropout rate for the certain municipality is higher than 25%.

3. Research on whether computer aided instruction is the same as lecture method

of a lesson presentation.

4. Research on smoking lessens the life span of a person.

5. Determine whether the mean monthly salary of call center agents is 25,000 a

month.

Answer 1

1. C (right-tailed test), because "improves children's thinking process" means that we believe that µ is more than value stated in $H_0$.
2. C (right-tailed test), because "is higher than 25%" means that the alternative hypothesis contains the “>” sign, so right-tailed test.
3. A(two-tailed test), because "whether computer aided instruction is the same as lecture method" means that computer aided instruction can be the same as.... or not the same as... So, we believe that µ is different from the value stated in $H_0$ . Hence, it is two-tailed test.
4. B (left-tailed test), because "smoking lessens the life span" means that we believe that µ is less than value stated in $H_0$ .
5. A(two-tailed test), because "whether the mean monthly salary is 25,000" means that it could be 25,000 or it couldn't be 25,000. So, we believe that µ is different from the value stated in $H_0$ . Hence, it is two-tailed test.