If, instead, the mass remained the same as the original problem, but the spring was replaced by one with a spring constant that was four times as large, the period would be:

T = so period of mass spring system becomes 2 times w.r.t original problem.

Explanation:

so when k = 1 is replaced by 4 it means it becomes

k" = 4k

grav force prop 1/r squared 2r all squared is 4rsquared 1/4rsquared quartered