Answer:
5
Step-by-step explanation:
Use the distance formula 
insert the numbers into the formula 
2+1=3 and 0-4=-4
=9 and
= 1
9+16=25
the square root of 25 is 5
Answer:

Step-by-step explanation:
Image of
is 
Image of
is 
Hence
corresponds to 
Answer:
Independent-samples t-test.
Step-by-step explanation:
We are looking for the appropriate design for testing the significance of the difference between the means.
Now, there is a parametric test known as the Independent Samples t Test and what this test does is that it compares the mean of two independent groups in order to find out whether there is statistical evidence that the related population mean is significantly different.
Thus, the test to be used here is Independent-samples t-test.
Answer:
a
Step-by-step explanation: