How to change the oscillation period of a spring pendulum if its mass is reduced by 4 times?

The oscillation period of the spring pendulum:
Т = 2Π * sqrt (m / k), m is the mass of the spring pendulum with a load (kg), k is the rigidity of the pendulum spring (coefficient of elasticity, N / m).
The period of oscillation of the spring pendulum before the mass decrease:
Т1 = 2Π * sqrt (m1 / k).
The period of oscillation of the spring pendulum after weight reduction:
T2 = 2Π * sqrt (m2 / k), m2 = 0.25m1.
T2 / T1 = 2Π * sqrt (0.25m1 / k) / 2Π * sqrt (m1 / k) = 0.5 / 0.1 = 0.5.
Answer: The period of oscillation of the spring pendulum will be halved.