Answer :

[tex]\frac { w }{ 7 } =0.3\\ \\ \frac { w }{ 7 } =\frac { 3 }{ 10 }[/tex]

[tex]\\ \\ 7\cdot \frac { w }{ 7 } =7\cdot \frac { 3 }{ 10 } \\ \\ w=\frac { 21 }{ 10 } \\ \\ \therefore \quad w=2.1[/tex]