For this you do Pythagorean theorem so
7^2+12^2=x^2
49+144=x^2
193=x^2
x=squareroot193
so you put 193 in the green box.
hope this helped❤️
Your 50 feet below sea level and then you go up 10 feet 5 times so the answer would be -10
D because it would give a non-biased sample group to fairly survey.