ANSWER:
The correct answer is
-This study is blind.
-This study is an experimental study.
STEP-BY-STEP EXPLANATION:
This study includes a controlled treatment (in this manner it is an investigation) and subjects didn't have a clue about the idea of the treatment so it is visually impaired.
B=-3.18 I hope that helps
The others are most likely correct it has been a while since I've worked with fractions
Answer:
50.24 or 50.272
Step-by-step explanation:
Square radius and then times by 3.14 or 3.142
4^2*3.14 = 50.24
4^2*3.142 = 50.272