The gcf of 18 and 20 is 2, so your answer is:
2(9+10)
The mean absolute deviation for the number of hours students practiced the violin is 6.4.
<h3>What is the mean absolute deviation?</h3>
The average absolute deviation of the collected data set is the average of absolute deviations from a center point of the data set.
Given
Students reported practicing violin during the last semester for 45, 38, 52, 58, and 42 hours.
The given data set is;
45, 38, 52, 58, 42
Mean Deviation = Σ|x − μ|/N.
μ = mean, and N = total number of values
|x − μ| = |45 − 47| = 2
|38− 47| = 9
|52− 47| = 5
|58− 47| = 11
|42− 47| = 5
The mean absolute deviation for the number of hours students practiced the violin is;

Hence, the mean absolute deviation for the number of hours students practiced the violin is 6.4.
To know more about mean value click the link given below.
brainly.com/question/5003198
Answer:
(4.25,6.5)
Step-by-step explanation:
First box is EF.
Second box is segment congruence postulate.
Third box is segment additon postulate.
Fourth box is DF. For this one the last sentence basically gives you the answer.
Just so you know for the fourth I guessed on if it's DF lined or DF unlined. I made my educated guess on the fact that the last line doesn't have a line. I hope this helps, and please tell me if I got something wrong, or my explanation wasn't sufficent enough for you.
The inscribed circle has its center at the point of intersection of the angle bisectors, which also happen to be the medians. Hence the altitude of the triangle is 3 times the radius, or 12 inches.
The side length of this triangle is 2/√3 times the altitude, so the area is
... Area = (1/2)·b·h = (1/2)·(24/√3 in)·(12 in)
... Area = 48√3 in² ≈ 83.1384 in²