Noise currents of radio tubes. How to calculate them?

Question

Electronics

Good afternoon. Need help with physics. Whoever does it can be rewarded. In the screenshot, apart from the first row and the first column, I'm not sure of anything.
1) So, the number of electrons bombarding the anode at different times can be both more and less than the average value. By analogy with alternating current, one can speak of the average amplitude of oscillations in the number of electrons. The wonderful physicist Poisson, whom you already heard about in the first semester, found that the average amplitude of the fluctuations in the number of particles is equal to the square root of the average number of particles. So, if the average number of electrons is 100, the amplitude of their number fluctuation is 10. Let's create a table with 5 columns. First, we will introduce the average number of electrons arriving at the anode in one second. Note that such currents are found in the characteristics of modern devices. Let's put this value in the second column of the table. In the third column, we write the average amplitude of oscillations of the number of electrons, which is approximately 3. In column 4 we write the average amplitude of the alternating current, that is, approximately 0.5 attoampere. In the last column of the table, we write the signal-to-noise ratio, which is equal to the ratio of the average and alternating currents. In the first line it is 3
HOMEWORK:
fill in the table for the average number of electrons arriving at the anode in 1 second: 100, 1000, Mega, Giga, Tera, Penta, Exa.