Determine whether y varies directly with x. If so, find the constant of variation k and write the equation.

X:
6
11
16
21

Y:
7.2
13.2
19.2
25.2

yes; k = 1.2; y = 1.2x
yes; k = 5; y = 5x
yes; k = 6; y = 6x
no

Question

Determine whether y varies directly with x. If so, find the constant of variation k and write the equation.

X:                
6
11
16
21

Y: 
7.2
13.2
19.2
25.2


yes; k = 1.2; y = 1.2x
		yes; k = 5; y = 5x
		yes; k = 6; y = 6x
		no

mani_jha · Answer

X and Y will have a direct variation if you can express it in the form of a straight line Y=mX+c.
You need to find m using the formula (y2-y1)/(x2-x1)
Take for example, y1= 7.2 y2=13.2 and x1=6 x2=11
Your job is to find the difference between any two consecutive values of X and difference between two consecutive values of Y. Now divide the difference in Y by difference in X. If the result is the same throughout, it is a direct variation. The constant of variation is the slope
Did you get this?

anonymous · Answer

1.2?