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.
Answer:
Q1. Regular (A)
Q2. 105° (C)
Q3. x=45°
Step-by-step explanation:
Q1. A regular polygon is a polygon with all sides and angles equal.
Q2. The sum of the measure of exterior angles of a polygon is always 360°. Therefore, 360°-255°=105°
Q3. 148°+112°+(2x+10)°+(2x)°+90°= Sum of angles in a pentagon.
<u><em>Note</em></u>: The square at the fifth angle shows that its a right angle which is 90°. Also all the angles are equal to the sum of angles in a pentagon 'cause the polygon has 5 sides ( a pentagon).
Sum of interior angles of a polygon is: (n-2)180°. Where "n" is the number of sides of the polygon.
Therefore the sum of interior angles is (5-2)180°=540°
solving the equation you have;
360°+4x=540°
4x=540°-360°
4x=180°
x=180°/4
x=45°
therefore x=45°
The answer would be B.
Add across : x + 6x = 7x
(x + 1) + (x + 5) = 2x + 6
So you get 7x / 2x + 6
You're pretty much screwed
