Question

Another project manager thinks the project management component of an IT project is smaller. This project manager would like to carry out a hypothesis test and test the claim that project management represents an average of less than 20 percent of an IT project. Why is their hypothesis test left-tailed?

a) Because they expect the project management component to be significantly larger
b) Because they are testing for the possibility of the project management component being smaller
c) Because they want to prove that project management represents exactly 20 percent
d) Because it is a standard practice in hypothesis testing

Answer 1

Hypothesis test left-tailed Because they want to prove that project management represents exactly 20 percent (option c)

Step-by-step explanation:

The hypothesis test in question is left-tailed because the project manager wants to test the claim that project management represents less than 20 percent of an IT project's workload. In hypothesis testing, the direction of the tail is determined by the alternative hypothesis (Ha). Since the manager expects the percentage to be lower, the alternative hypothesis would be Ha: μ < 0.20, where μ represents the true average percentage of project management in IT projects. The left-tailed test is appropriate when checking for values significantly lower than a benchmark. If the result from the hypothesis test reveals a small p-value, it would indicate strong evidence against the null hypothesis, suggesting that the project management component is indeed smaller than 20 percent.

A 'left-tailed' hypothesis test is used because the manager wants to test if the project management part is less than 20 percent, and a small p-value would indicate evidence against the null hypothesis suggesting a smaller project management component.