The standard error of the sample mean is defined as: Alpha The population standard deviation Median The sample standard deviation, divided by n-1. The sample standard deviation, divided by the square root of n. D Question 10 3 pts With a 95% confidence interval for the mean that goes from a lower value of 107 to an upper value of 135, the margin of error would be _? (use one decimal) D Question 11 3 pts A statistician wants to test the true age of students at the University of Tennessee. They sample 107 students and find a sample mean of 21.5 with a standard deviation of 0.5. What are the degrees of freedom for this test?