If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

# Writing hypotheses for a test about a mean

AP.STATS: VAR‑7 (EU), VAR‑7.C.1 (EK), VAR‑7.C.2 (EK)

## Problem

A school counselor heard that teenagers sleep an average of 9 hours per night on the weekend. The counselor wants to test if this figure holds true for students at their school, so they take a random sample of students and ask them about their weekend sleep habits.
Let mu represent the average amount of sleep that students at this school get per night on the weekend.
Which of the following is an appropriate set of hypotheses for their significance test?