Find a model for the situation and use the model to answer the question:
the number of students enrolled in a school district was 8500 in 2010. enrollment has been dropping by 4% each year since that time. predict the enrollment in 2016.

Rachel is studying the population of a particular bird species in a national park. she observes every 10th bird of that species that she can find in the park. her conclusion is that the birds living in the park who belong to that species generally feed on insects. rachel's sample is . based on the sample she picked, rachel's generalization is