Problem 5. The lifetime of a device behaves according to exponential probability law, with α =...
Let X be the lifetime of an electronic device. It is known that the average lifetime of the device is 747 days and the standard deviation is 108 days. Let be the sample mean of the lifetimes of 164 devices. The distribution of X is unknown, however, the distribution of a should be approximately normal according to the Central Limit Theorem. Calculate the following probabilities using the normal approximation (a) Pa s 737) (c) P(737 i 763): Check
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...
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?
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 5. Let X be a continuous random variable with a 2-paameter exponential distribution with parameters α = 0.4 and xo = 0.45, ie, ;x 2 0.45 x 〈 0.45 f(x) = (2.5e-2.5 (-0.45) Variable Y is a function of X: a) Find the first order approximation for the expected value and variance of Y b) Find the probability density function (PDF) of Y. c) Find the expected value and variance of Y from its PDF
Problem 5. Let X...
There are two fuses in an electrical device. Let X denote the lifetime of the first fuse, and let y denote the lifetime of the second fuse both in years). Assume the joint probability density function of X and Yis f(x,y) – $(x +2y). 0<x<1, 0 <y<2 a. What is the probability that both uses last longer than 4 months? b. What is the probability that the second fuse lasts less than 3 months given that the first fuse last...
There are two fuses in an electrical device. Let X denote the lifetime of the first fuse, and let y denote the lifetime of the second fuse (both in years). Assume the joint probability density function of X and Y is f(x,y) = (x? + 2 + 2) 0<x< 1, 0 < y < 2 a. What is the probability that both fuses last at most 4 months? b. What is the probability that the first fuse lasts less than...
A critical part of a machine has an exponentially distributed lifetime with parameter α. Suppose that n spare parts are initially at stock, and let N(t) be the number of spares left at time t. (a) Find P(N(s + t) = j | N(s) = i). (b) Find the transition probability matrix. (c) Find Pj (t). in Pj(t) j is in lower script
Problem 4: Memoryless Property of Exponential Random Variable The lifetime of a stream of electrons injected in a p-type semiconductor follows an exponential distribution with a mean value of 1 ms. Assuning that an electron injected in this semiconductor has survived for 2 ms, what is the probability that this electron survives for an additional 1 ms?
Problem 3 (Needed for Problem 4) A continuous random variable X is said to have an exponential distribution, written Exp(X), if its probability density function f is such that le- if > 0 10 if x < 0 f(0) = 0 where > 0 is a real number. 1. Compute the mean of X 2. Compute the variance of X 3. Compute the cumulative distribution function F of X. Use this to show that for any real numbers s and...