1)
epxected value E(X)=x f(X) dx =(x/100)e-x/100 dx
=(-(x/100)*100*e-x/100-(1/100)*1002*e-x/100))|0 =100
2)
expected life =E(X)= x f(x) dx =(4/)*(x/(1+x2)) dx
let (1+x2 ) =t
differentiating above with respect to x:
2x =dt/dx
xdx =dt/2
for x=0 ; t=1
and for x=1 ; t-2
theefore E(X)=(4/)*(x/(1+x2)) dx =(4/)*(1/2)*(1/t)* dt =(2/)*(ln(t)|21 =(2/)*(ln(2)-ln(1))
E(X)=2ln(2)/
Thank you! 1) Let X be the life (in hours) of a certain electronic device. The...
Let X be the lifetime of a certain type of electronic device (measured in hours). The probability density function of X is f(x) =10/x^2 , x > c 0, x ≤ c (a) Find the value of c that makes f(x) a legitimate pdf of X. (b) Compute P(X < 20).
Problem 4. The life X, in hours, of a certain device, has a pdf 100 , t 100 0, t< 100 (a) What are the probability that this device will survive 150 hours of operation? (b) Find the life expectancy of the device.
Problem 4. The life X, in hours, of a certain device, has a pdf 100 0, < 100 (a) What are the probability that this device will survive 150 hours of operation? (b) Find the life expectancy of the device.
3. (25 pts) The life X, in hours, of a certain kind of electronic part has a probability density function given by fory 2100 f,(y) o, fory <100 (A) What is the probability that a part will survive 250 hours of operation? (B) Find the expected value of the random variable (C) Find the variance of the random variable if the probability density function is given by y 2100 0, y<100.
Assume the life of an electronic component in hours is a random variable with the following density function: 9. f(x)-(01 ge-./soo, elsewhere. Find the following: (a) The mean life of the electronic component, (b) Find E(X2), (c) Find the variance and standard deviation of the random variable X. (d)Demonstrate that Chebyshev's theorem holds for k = 2 and k = 3. Assume the life of an electronic component in hours is a random variable with the following density function: 9....
The probability density function of X, the lifetime of a certain type of electronic device (measured in hours), is given by fX(x) = ( C/x^2 x>5 0 x<5 where C>0 is a constant which needs to be determined. (i) What is the probability that the device’s lifetime is 10 hours? (ii) Find the 25%th quantile of X? (iii) If the device lifetime is X, then its total electricity cost equals . What is the expected total electricity cost of the...
15. Let X and Y denote the lengths of life, in hundreds of hours, for co ponents of typesI and types II, respectively in an electronic system. The joint density of X and Y is given by Bre" (z +v)/2 f(z, y) = otherwise Find the probability that a component of type II will have a life lenght in excess of 200 hours. 16. Let the random variables X and Y have the joint p.d.f a. f(z,y)=ī, for (z,y) =...
Problem 1 The pdf of X, the lifetime of a certain type of electronic device in hours, is given by if x > 10 10 if x < 10 f(x) = { ift 1. (1 point) Find the constant c that makes the a valid pdf. 2. (1 point) Find P(X > 20) 3. (1 point) Find F(x), i.e. the cummulative distribution of X? 4. (1 point) What is the median value of X?
please do them both for high rate Problem 3. Let X be a discrete random variable, with probability distribution P(X x)0.95, P(Xx2) 0.05 Determine X1 and X2 such that E[X] 0 and σ2(X)-7. Problem 4. The life X, in hours, of a certain device, has a pdf 100 x()t2 2 100 0, t<100 (a) What are the probability that this device will survive 150 hours of operation? (b) Find the life expectancy of the device.
The shelf life, in days, for bottles of a certain prescribed medicine is a random variable having the density function 20,000 f(x) = (x + 1003: *>0 lo, elsewhere Find the probability that a bottle of this medicine will have a shell life of at least 100 days.