The frequency response H(f) of a linear time-invariant system has magnitude as shown in the figure.

Statement I : The system is necessarily a pure delay system for inputs which are bandlimited to $$-$$$$\alpha$$ $$\le$$ f $$\le$$ $$\alpha$$.

Statement II : For any wide-sense stationary input process with power spectral density S_X(f), the output power spectral density S_Y(f) obeys S_Y(f) = S_X(f) for $$-$$$$\alpha$$ $$\le$$ f $$\le$$ $$\alpha$$.

Which one of the following combinations is true?

Consider the random process
x(t) = U + Vt.
Where U is a zero mean Gaussian random variable and V is a random variable uniformly distributed between 0 and 2. Assume that U and V are statistically independent. The mean value of the random process at t = 2 is _________________

If calls arrive at a telephone exchange such that the time of arrival of any call is independent of the time of arrival of earlier or future calls, the probability distribution function of the total number of calls in a fixed time interval will be

The power spectral density of a real process X(t) for positive frequencies is shown below. The value of $$E\,\left[ {{X^2}\,(t)} \right]$$ and $$E\,\left[ {X\,(t)} \right]$$, respectively, are