Answer:
5.025%
Explanation:
When we assume that the pure expectations theory is correct, then we are assuming that there is no risk premium involved. The formula to determine the yield for the 2 year treasury security:
(1 + i)² = (1 + 4.85%) x (1 + 5.2%)
(1 + i)² = 1.0485 x 1.052
(1 + i)² = 1.103022
√(1 + i)² = √1.103022
1 + i = 1.050248542
i = 0.050248542 = 5.025%