Let X be the amount Mr Saver invests at t = 0.
The interest he earns during t = 0 to t = 1 can be expressed as:
Interest = X * R * (1/4)
The interest he earns during t = 0.5 to t = 1.5 can be expressed as:
Interest = X * R * (3/4)
Since the interest he earns during t = 0.5 to t = 1.5 is 1.0816 times the interest he earns during t = 0 to t = 1, we can set up the following equation:
X * R * (3/4) = 1.0816 * (X * R * (1/4))
Solving for R, we get:
R = 4.3264 Therefore, the exact value of R