The answer is 4.5 years
Given : semi annual bond
current market price : $988.52
par value : $1,000
maturity : 5.29%
PMT = 5% x $1000 / 2 = $25,
PV = $988.52,
FV = $1000, and
Int/half a year = 5.29%/2 = 2.645%.
Solving for N = 9 (semi annual periods).
9/2 = 4.5.