First of all, this is not an observational study, but an experiment, since we have two groups and one of the two groups is manipulated or treated. In an observational study the subjects are only observed.
Second, the students did not choose their groups - so we can't choose the last answer.
Therefore the correct answer is:
This is an experiment because a treatment was applied to a group.
I would use 100 as the denominator because it can not be simplified as a whole number
The total sum is 180 because 3 angles = 180
54 + 11s + 7s = 180
-54. -54
18s = 126
S = 7
<h3>
Answer: 72</h3>
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Explanation:
The angle x is a base angle of the isosceles triangle. The unmarked angle is also x, since the base angles of isosceles triangles are congruent.
For any triangle, the three angles always add to 180
x+x+36 = 180
2x+36 = 180
2x = 180-36
2x = 144
x = 144/2
x = 72