The sampling method used in the situation of the quality control analyst in his attempt to avoid staying after work would be a non-probability sampling method. He used a nonprobability sampling called convenience sampling wherein the person gets a sample for easy and convenient results.
To solve for the last side of the triangle, use the Pythagorean Theorem:
(8)^2 + x^2 = (9)^2
x = sqrt of 17
However, this is a NEGATIVE sqrt 17 because the terminal side is in quadrant 4, meaning that this side is under the X-axis and therefore negative.
Now that you know the side opposite of u in the triangle, do opposite/hypotenuse.
sin u = -(sqrt 17)/9
C=0.05(125000)+500
C=6250+500
C=6750
comission is $6750
The angle the radius makes with AB is a right angle, so the Pythagorean theorem applies.
r² = 17.4² - 7² = 253.76
r = √253.76 ≈ 15.9
The length of radius r is about 15.9.