I will assume that the diameter of a real basketball is 30 cm
and the diameter in the drawing of the basketball is 5 cm
To find out the scale factor
you must divide the measure in the drawing by the measure in the real
so
scale factor=5/30
scale factor=1/6
that means
1 cm in the drawing represent 6 cm in the real
or
the measure of the real is six times the mesure in the drawing