Question

4. Jane and Sally make phone calls whose lengths are independent and identically distributed exponential random...

4. Jane and Sally make phone calls whose lengths are independent and identically distributed exponential random variables with mean 3 minutes. Assuming the calls begin at the same time, what is the expected time until both are completed?

Homework Answers

Answer #1

here let parameter of 1st and 2nd phone calls are 1 and 2

from above 1 =2 =1/3

therefore expected time until both are completed =1/1+1/2-1/(1+2) =1/(1/3)+1/(1/3)-1/(3+3) =3+3-3/2 =4.5 minutes

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
Let X and Y be independent and identically distributed random variables with mean μ and variance...
Let X and Y be independent and identically distributed random variables with mean μ and variance σ2. Find the following: a) E[(X + 2)2] b) Var(3X + 4) c) E[(X - Y)2] d) Cov{(X + Y), (X - Y)}
Problem 3. Let Y1, Y2, and Y3 be independent, identically distributed random variables from a population...
Problem 3. Let Y1, Y2, and Y3 be independent, identically distributed random variables from a population with mean µ = 12 and variance σ 2 = 192. Let Y¯ = 1/3 (Y1 + Y2 + Y3) denote the average of these three random variables. A. What is the expected value of Y¯, i.e., E(Y¯ ) =? Is Y¯ an unbiased estimator of µ? B. What is the variance of Y¯, i.e, V ar(Y¯ ) =? C. Consider a different estimator...
STAT 180 Let X and Y be independent exponential random variables with mean equals to 4....
STAT 180 Let X and Y be independent exponential random variables with mean equals to 4. 1) What is the covariance between XY and X. 2) Let Z = max ( X, Y). Find the Probability Density Function (PDF) of Z. 3) Use the answer in part 2 to compute the E(Z).
Suppose a chandelier has 2019 bulbs, each has independent random lifetimes that is uniformly distributed on...
Suppose a chandelier has 2019 bulbs, each has independent random lifetimes that is uniformly distributed on an interval [0,β] with the same variance as an exp(1/4) variable. (You have to figureout the value of β.) Find the expected time until 2001 bulbs have burned out.
1. If X  is a normal distributed random variable with population mean 5 and population variance 4...
1. If X  is a normal distributed random variable with population mean 5 and population variance 4 , the probability that X  is lies between 1 and 7 is closest or equal to 0.0228 0.8185 0.1815 0.8413 2. Suppose X1  and X2  are both normally distributed random variables with population mean 10 and population variance 4. If X1  and X2   are independent, the probability that average of X1  and X2  lies between 8 and 12 is closest or equal to X2 0.9214 0.0786 0.1572 0.8428 3. A...
1. (10 pts) If A and B are independent events (both with probability greater than 0)...
1. (10 pts) If A and B are independent events (both with probability greater than 0) then which of the following statements must be true? A. P(A) + P(B) = 1 B. P(A and B) = P(A)P(B) C. P(A and B) = 0 D. P(A and B) = P(A) + P(B) 2. (10 pts)A salesperson makes “cold calls” trying to sell a product by phone and is successful on each call with probability 1/50. Whether or not he is successful...
Let X1, X2 be two normal random variables each with population mean µ and population variance...
Let X1, X2 be two normal random variables each with population mean µ and population variance σ2. Let σ12 denote the covariance between X1 and X2 and let ¯ X denote the sample mean of X1 and X2. (a) List the condition that needs to be satisfied in order for ¯ X to be an unbiased estimate of µ. (b) [3] As carefully as you can, without skipping steps, show that both X1 and ¯ X are unbiased estimators of...
Solutions for this exercise will not be posted. However, it is possible that questions from this...
Solutions for this exercise will not be posted. However, it is possible that questions from this exercise could appear on Midterm II. DEFINE ALL NOTATION!!!!! 1. Here is a pdf: . a) How do you know it is a continuous distribution? b) The constant a is positive. What is a? c) What is probability that the random variable X is equal to 1? d) What is F(-0.5)? e) What is the cdf of the random variable X? f) What is...
Multiple Choice Select the best answer from the available choices for each question. Which of the...
Multiple Choice Select the best answer from the available choices for each question. Which of the following is NOT part of the definition of a sample space S? S can be discrete or continuous Each outcome must be in S at most once Each element in S is equally likely Each outcome must be in S at least once S is a set of possible outcomes in an experiment Three A’s, three B’s, and two C’s are arranged at random...
  Canadian Whisky: Capitalizing on World Recognition A Thirst for More Rick Clemens opened an independent whisky...
  Canadian Whisky: Capitalizing on World Recognition A Thirst for More Rick Clemens opened an independent whisky distillery 15 years ago in a small town in British Columbia, Canada. Since that day, his business has slowly grown, gaining first a local, then regional and finally national following. It has since grown from a two-person operation to a thriving business with an in-house team of six and the contracted services of an off-site bottler and distributor. After many years of operating at...