megan wants to test her assumption on the amount of sleep students are getting. she decides to focus her efforts on examining if students are getting less than eight hours of sleep. what should megan state for the null hypothesis and alternative hypothesis? a.) null hypothesis: mu equals 8 alternative hypothesis: mu less than 8 b.) null hypothesis: mu less than 8 alternative hypothesis: mu greater than 8 c.) null hypothesis: mu equals 8 alternative hypothesis: mu not equal to 8 d.) null hypothesis: mu less than 8 alternative hypothesis: mu not equal to 8