the question says that the samples included 100 people each, so it's just 100 multiplied by the amount of samples:
7×100=700
What is this? may I ask? did you mean to attach a photo?
Answer:
I do not know, but I do know the formula.
The formula is: 12pl+B where p represents the perimeter of the base, l the slant height and B the area of the base.
For number one the answer is A 2,880
for number two the answer is C 75% <--- i guessed
hope this helped