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.

The variable $x$ is directly proportional to the variable $t$. When $t=4.6, x=3.45$. Write down the function relating $t$ and $x$.

The variable $x$ is directly proportional to the variable $t$. When $t=4.6, x=3.45$. Find $x$ when $t=8.2$

$P$ is inversely proportional to $y$. When $P=15,y=0.2$. Find $P$ when $y=1.5$.

$M$ varies directly as the square of $c$. When $M=12.6, c=3$. When $M=17.15$, find $c$, where $c>0$.