Answer
$\beta = 0.99995000 $
Work Step by Step
lorentz factor $\gamma=100$
We know that the formula for lorentz factor is;
$\gamma =\frac{1}{\sqrt (1-\frac{1}{\beta^2})}$
The speed parameter $\beta =\sqrt (1-\frac{1}{\gamma^2})$
We substitute $\gamma$ value i,e 100 in above formula and solve;
$\beta =\sqrt (1-\frac{1}{100^2})$
$\beta = 0.99995000 $