X(t), the input to a linear time-invariant filter is a wide sense stationary stochastic process with expected value µX = 4 volts. The filter output Y(t) is a wide sense stationary stochastic process with expected µY = 1 volt. The filter impulse response is
![](https://test.transtutors.com/qimg/c3069ac7-f0be-4256-a271-d4d6cb0e49fd.png)
What is the value of the time constant a?