Research Description #4: According to the National Science Foundation, young adults aged 18-25 need to sleep for 7-9 hours each night. On average, however, adults in this age range report sleeping for less than the recommended length: the mean = 6.8 hours, and the standard deviation = 0.75. Sleep researchers at the University of Cincinnati were interested in whether UC students aged 18-25 sleep more or less than average. They gather a sample of 100 students and survey each student about their sleep behaviors. They find that UC students sleep, on average, for 7.0 hours each night (standard deviation = 1.20). What is the null hypothesis