The mean number of hours teenagers are supposed to sleep is 7.5 hours per night. A high school administrator believes one of the reasons students at the school are struggling is because they do not get enough sleep. To test this, the administrator selected a random sample of 40 students from all of the students at school and
asked how many hours of sleep they got last night. The sample mean was 6.75 hours and the sample standard deviation was 1.75 hours. What is the standardized test
statistic for the significance test the school administrator wants to perform?
O t= -0.4286
O t= -2.7105
O t = 0.4286
O t=2.7105