organization reported that teenagers spent 4.5 hours per week, on average, on
the phone. The organization thinks that, currently, the mean is higher. Fifteen
randomly chosen teenagers were asked how many hours per week they spend on the
phone. The sample mean was 4.75 hours with a sample standard deviation of 2.0.
Conduct a hypothesis test.
The null and
alternative hypotheses are:
Ho: x ¯ = 4.5, Ha: x ¯ > 4.5
Ho: ? ? 4.5, Ha: ? < 4.5
Ho: ? = 4.75, Ha: ? > 4.75
Ho: ? = 4.5, Ha: ? > 4.5