Sketch the graph of the given variation function and determine whether it is a direct or inverse relationship.

$y=5x$

Sketch the graph of the given variation function and determine whether it is a direct or inverse relationship.

$y=\frac{x}{3}$

Sketch the graph of the given variation function and determine whether it is a direct or inverse relationship.

$y=1.4x^2$

Sketch the graph of the given variation function and determine whether it is a direct or inverse relationship.

$y=\frac{2}{x^2}$

Sketch the graph of the given variation function and determine whether it is a direct or inverse relationship.

$y=\frac{7}{x}$

Sketch the graph of the given variation function and determine whether it is a direct or inverse relationship.

$y=\frac{1}{3x}$

Sketch the graph of the given variation function and determine whether it is a direct or inverse relationship.

$y=\frac{3x^2}{5}$

Sketch the graph of the given variation function and determine whether it is a direct or inverse relationship.

$y=\frac{3}{5x^2}$

The variable $x$ is directly proportional to the variable $t$. When $t=4.6, x=3.45$. Find the value of the constant of proportionality in decimal.