Answer: Choice B) 
Work Shown:

Note: secant is positive in quadrant Q4, when theta is between 3pi/2 radians and 2pi radians (270 degrees and 360 degrees). So that's why we don't consider the minus form of the plus minus.
Numbers that are close in value to the actual numbers
Answer:
You know this because $110x20%=$22.
1. Mean is the number you get when you add all these numbers and then divide by the number of numbers. So, (31 + 28 + 30 + 31 + 30) / 5 = 150 / 5 = 30
2. The median is the middle number in the list of numbers, so, the answer is 30 as well.
3. Mode is the number that appears most often, so here it is 30 and 31 because they both appear 2 times.
4. Range is the difference between the largest and smallest number, so 31 - 28 = 3.