To determine the favorite after school activity of 7th-grade students in Ms. Smith's school, she should sample the population of all 7th-grade students in her school.
Sampling from this population would allow her to gather data on the after-school activities that are most popular among 7th-grade students in her school. She could then use this data to inform decisions about programs and activities that could be offered to students.
To ensure that the sample is representative of the population, Ms. Smith could use random sampling techniques to select a subset of 7th-grade students from her school. She could then survey these students to gather information on their favorite after-school activities. It's important to ensure that the sample is large enough to provide reliable data on the population. A larger sample size would generally produce more reliable results.