Abasketball referee tosses the ball straight up for the starting tip-off. at what velocity (in m/s) must a basketball player leave the ground to rise 1.23 m above the floor in an attempt to get the ball?

The formular for solving this equation is 
mgh = mv^2/2
The M on both sides of the equation stand for mass and the two of them cancel each other out and the equation becomes:
gh = V^2 / 2
g = 9.8 m/s
h = 1.23 m
V ?
V is the velocity that we need to find, so we are going to make V the subject of the formular:
V = Square root of 2gh = square root of [2 * 9.8 * 1.23] = square root of [24.108]= 4.9 
Thus, the velocity = 4.90 m/s