How does sample size affect the width of a confidence interval?

A colleague has calculated a 95% confidence interval about the sample mean as: 16 < u < 25. What interpretation should your colleague make? 

A researcher has collected some data related to a new method of teaching reading. She conducted an independent means t-test and failed to reject the null hypothesis at alpha=.05. She calculated a sample effect size (d) of 0.90. What advice is the best regarding the results of this research?

Based on the above results, the appropriate p-value for the test that the population means are equal is:

Drs. Smith and Jones each collect identical data and each conduct an independent-means t-test. Dr. Smith uses an alpha level of 0.05, but Dr. Jones insists on an alpha of 0.001. Which of these researchers has greater power in her test of the null hypothesis?

Use the following information for items 37 and 38. Scenario: A researcher is comparing two independent groups of test scores. The following descriptive statistics are given when an independence t-test procedure is run. Assume α = .05. Question: What is the pooled standard deviation?

If your colleague wanted to reduce the width of a confidence interval without reducing the level of confidence, she should

The nurse researcher is interested in using nominal-level data. The object or event that could be used if nominal-level data are of primary interest is:

What is the default firewall command used to open ports in Ubuntu. 

Frank, who has schizophrenia, allegedly severely beat another man after an argument. While he is being examined by a psychologist to see if he is fit to stand trial, he is being held at a state forensic psychiatric hospital. This is an example of