Adrill instructor recorded the time in which each of 11 recruits completed an obstacle course both before and after basic training. to test whether any improvement occurred, the instructor would use a t distribution with 11 degrees of freedom.

In this problem, it is TRUE that the instructor would need to use a t distribution with 10 degrees of freedom to be able to test whether any improved occurred.

In order to check for its correctness, we need to measure the absolute difference between the mean value in two groups in a clinical trial by using the mean difference. Next, we check for the degrees of freedom. The degrees of freedom are the number of independent pieces of information that went into calculating the estimate.

You have to subtract 1 from the number of items to be able to get the df for the estimate. Let’s check this scenario:

Let’s say you need to find the mean weight loss for a low carbohydrate diet. You can use 4 people and giving 3 degrees of freedom (4 -1 = 3), in turn, you can also use 100 people with a df of = 99.

the answer

b. they are parallel and will never intersect.