Making use of the cube root table,

We have:

$9800=98 \times 100$

$\therefore \sqrt[3]{9800}=\sqrt[3]{98 \times 100}=\sqrt[3]{98} \times \sqrt[3]{100}$

By cube root table, we have: 

$\sqrt[3]{98}=4.610$ and $\sqrt[3]{100}=4.642$

$\therefore \sqrt[3]{9800}=\sqrt[3]{98} \times \sqrt[3]{100}=4.610 \times 4.642=21.40$ (upto three decimal places)

Thus, the required cube root is 21.40.