Answer:
Option B) 16
Step-by-step explanation:
We are given the following in the question:

where x is the student's original test score and y is the student's adjusted test score.
We have to find the standard deviation of the adjusted test scores of the students in the class, if the standard deviation of the original test scores of the students in the class was 20.
We know that:
- Adding a constant to each value in a data set does not change the value of the standard deviation.
- Multiplying each value in a data set by a constant also multiplies the standard deviation by that constant.
Thus, if we add 20 to each data set then, the standard deviation does not change.
But multiplying each score by 0.8, changes the standard deviation 0.8 times.
Thus, we can write:

Thus, standard deviation of adjusted score is 16.
Answer:
5 presents
Step-by-step explanation:
40 presents in 2 hours
20 presents in 1 hour (divide by 2)
20 presents in 60 minutes ( 1 hour is 60 minutes )
5 presents in 15 minutes ( divide by 4)
Answer:
No solutions
Step-by-step explanation:
Step: Solve−3x+7y=−12 for x:
Step: Substitute
0 = -12 so No Solutions
For this kind of questions, what you can do is to find a point on the figure and see what translations it does.
For example, you can find the point (4,2) on the figure H. And then look at each choices to see if the statement is correct.
For this question, the answer is B. The point (4,2) finally change to the (4,-8) on the figure H'. It has a vertical translation of 10 units down.