Cross all correct statements of a proportional function.

# Direct proportionality & rule of three

Reasoning
7

#### Proportional graph

Select the graph of a proportional function.

# Direct proportionality & rule of three

Reasoning
7

#### The Bridge

One can describe the railway bridge as quadratic function $f(x)=ax^2+bx+c$. Calculate the value of the factor $a$ in the term of the quadratic function. Note: One meter is equal to one unit of length. Round to two decimal numbers.