Adding all the marks and dividing them by the total no. of students to get the average marks.
Avg. marks = (7+8+7+9+6)/5
Avg. marks = 37/5
Avg. marks = 7.4
That would be 8, its in the center so forget 9 or 7.
1st, find the mean of all values. 1+2+3+4=10 10/4=2.5 The mean is 2.5.
2nd, find the distance of each value from the mean. So 2.5-1=1.5; the distance between 1 and 2.5 is 1.5. Repeat it for all of them, and you get 1.5, .5, .5, and 1.5.
3rd, you take each distance and find the mean. 1.5+.5+.5+1.5=4 4/4=1 The mean deviation is 1.
You would add the x to both sides, cancelling out the x on the side with 2y. Then you divide by 2 leaving you with y=1/2x+3
It's 67/100 because a percent is out of 100 which is already simplified