Percentage increase is 300%.
| $\text{\% increase} = \dfrac{ \color{red}{ \text{final value} } - \color{blue}{ \text{initial value} } }{ \color{blue}{ \text{initial value} } } \times 100$ | $$ \begin{aligned} \color{red}{ \text{final value} } &= 3000000 \\[1.5em] \color{blue}{ \text{initial value} } &= 750000 \end{aligned} $$ |
| $\text{\% increase} = \dfrac{ \color{red}{ 3000000 } - \color{blue}{ 750000 } }{ \color{blue}{ 750000 } } \times 100 $ | |
| $\text{\% increase} = 3 \times 100 $ | |
| $\text{\% increase} = 300 \% $ |