Step-by-step explanation:
3x - 9 +2x + 9 = 2x - 2
5x = 2x - 2
5x - 2x = - 2
3x = - 2
x= - 2/ 3
interior angle of a regular 18-gon.
It is easier to calculate the exterior angle of a regular polygon of n-sides (n-gon) by the relation
exterior angle = 360/n
For a 18-gon, n=18, so exterior angle = 360/18=20 °
The value of each interior angle is therefore the supplement, or
Interior angle = 180-20=160 degrees.
Naming of a 9-gon
A polygon with 9 vertices is called a nonagon (in English) or enneagon (French ennéagone, but the English version is sometimes used)
You had a good start with the correct answer.
Exterior angle of a 15-gon
The exterior angle of a 15-gon can be calculated using the relation given in the first paragraph, namely
Exterior angle = 360/15=24 degrees
I believe the correct answer would be A. The best correlation to use to measure the relationship between gender and grade point average for a group of college students would be the point-biserial correlation. It is coefficient that is used when a variable is dichotomous or that the variable is part of a whole set. It is used in measuring the direction of the correlation that is present between a dichotomous variable and a continuous variable. From the question, the dichotomous variable would be the grade point average for a group of college students while the other variable is the continuous one.