Answer:
Option A
Step-by-step explanation:
The response variable is the dependent variable whose variation depends on other variables and in this case it is the type of surgery either total knee replacement or partial knee replacement.
While the explanatory variable which is the independent variable manipulated by the researcher for the given experimental study is the amount of activity the patients were able to do after their respective surgeries.
Answer:

Step-by-step explanation:
In order to find the answer to this question you must simply divide.





Hope this helps
Answer:
standard error of the mean = 1.6960
Step-by-step explanation:
Given -
Mean
= 53 minutes
Standard deviation ( s ) = 53.9 minutes
n = 1010
standard error of the mean =
=
= 
= 1.6960
Here is the answer to your question as This is the way I think it is solved