Determine whether y varies directly with x. If​ so, find the constant of variation and write the function rule.

x
27
30
57
y
9
10
19

What is the constant of​ variation? Select the correct choice and fill in any answer boxes in your choice below.

A.
k
  
enter your response here ​(Simplify your answer. Type an integer or a​ fraction.)
B.
There is no constant of variation.

To determine if y varies directly with x, we need to check if the ratio between y and x remains constant.

For example, let's calculate the ratios for the given data points:

27/9 = 3
30/10 = 3
57/19 = 3

The ratios are all equal to 3. Therefore, y varies directly with x.

The constant of variation (k) can be found by taking any ratio:

k = y/x = 9/27 = 1/3

So, the constant of variation is 1/3.

The function rule for direct variation is y = kx. Thus, in this case, the function rule is y = (1/3)x.

What is the function​ rule? Select the correct choice and fill in any answer boxes in your choice below.

A.
y=
  
enter your response here
​(Simplify your answer. Use integers or fractions for any numbers in the​ expression.)
B.
There is no function rule.

The correct function rule is:

A. y = (1/3)x