Do males spend less time on Facebook than females A random s

Do males spend less time on Facebook than females? A random sample of 100 male and females was selected. Let muf be the population mean number of hours spent online in facebook for females and let mum be the population mean number of hours spent online in facebook for males. How should we write the alternative hypothesis?

Solution

We desire to prove the alternative hypothesis, which is that males spend less time on facebook.

Thus,

Ha: mum - muf < 0 [ANSWER, C]