Question

For each of the following questions, decide whether or not the sample data can be used to construct a confidence interval.

How do I go about determining if the sample data can be used to construct a confidence interval?

Example:

To help consumers assess the risks they are taking, the Food and Drug Administration (FDA) publishes the amount of nicotine found in all commercial brands of cigarettes. A new cigarette has recently been marketed. The FDA tests on this cigarette gave a mean nicotine content of 24.2 milligrams and standard deviation of 2.7 milligrams for a sample of n = 9 cigarettes.

Answer 1

Since the sample size is small in your example, you would most likely need to use the t-distribution when constructing a confidence interval to account for the smaller sample size.