Thread: A Probability Question

Adsız.jpg
The following voltage waveform is to be sampled at a random time τ over a period of .
a)What is the probability of that the sampled value v(t) <-0,5
b)What is the probability of that the sampled value v(t)>1.25
c)What is the probability of that the sampled value v(t)=1,25
d)What is the probability of that the sampled value v(t)= -0,5

c) 0.1, d) 0.3. I'll leave the others for you.

d) must be 0

In practice, the probabilities depend on the accuracy of the measurement of v during the sampling process. If you don't take this into account, I wouldn't be surprised if you could construct some anomalies, since the probability of finding any one point on a sloping straight line will be 0, and the probability of finding a position somewhere along the line will be greater than zero.

yes it is true. But I wonder while solving this problem is, what process do we use?

Originally Posted by mecnun9

yes it is true. But I wonder while solving this problem is, what process do we use?

The conceptually simplest way is to get the probability of getting a value between v- /2 and v + /2, and at the end of your calculation take the limit as goes to zero. Then to cover a region with measurements at a "point at a time," the points will be a distance apart. With care, you will get no anomalies. In real life, you could take to be the measurement error in your instrument and sum rather than integrate.

Originally Posted by mecnun9

d) must be 0

You're right - I misread the picture. Somehow I saw it constant for an interval.