Statistics: a Process of Making Inferences Practice Test

A school wants to estimate the proportion of all students at the school who bring lunch from home on a typical day. The office randomly selects 80 student IDs from the full student roster and asks those students whether they brought lunch from home today; 52 say yes. Why is random sampling important in this situation?

A town wants to estimate the proportion of all households in the town that have a backyard garden. A researcher randomly selects 150 addresses from the town’s address database and finds that 45 of the selected households report having a backyard garden. Which statement is a reasonable inference?