<span>valid. She used a representative sample
</span>because she correctly found the average and 18,000 is a reasonable number to get for a the problem
Answer: Fraction of twins = 
Fractions of triplets = 
Fractions of quadruplets = 
Step-by-step explanation:
Since we have given that
Number of set of twins = 5
Number of sets of triplets = 2
Number of sets of quadruplets = 1
Total number of sets is given by
Now, we need to find the fraction of those students.
So, Fraction of twins is given by
Fractions of triplets is given by
Fractions of quadruplets is given by
A <span>counterclockwise rotation of 270º about the origin is equivalent to a </span><span>clockwise rotation of 90º about the origin.
Given a point (4, 5), the x-value, i.e. 4 and the y-value, i.e. 5 are positive, hence the point is in the 1st quadrant of the xy-plane.
A clockwise rotation of </span><span>90º about the origin of a point in the first quadrant of the xy-plane will have its image in the fourth quadrant of the xy-plane. Thus the x-value of the image remains positive but the y-value of the image changes to negative.
Also the x-value and the y-value of the original figure is interchanged.
For example, given a point (a, b) in the first quadrant of the xy-plane, </span><span>a counterclockwise rotation of 270º about the origin which is equivalent to a <span>clockwise rotation of 90º about the origin will result in an image with the coordinate of (b, -a)</span>
Therefore, a </span><span>counterclockwise rotation of 270º about the origin </span><span>of the point (4, 5) will result in an image with the coordinate of (5, -4)</span> (option C)
