Concept explainers
Find the expected values and the standard deviations (by inspection) of the normal random variables with the density functions given in Exercises 15–18.
![Check Mark](/static/check-mark.png)
Want to see the full answer?
Check out a sample textbook solution![Blurred answer](/static/blurred-answer.jpg)
Chapter 12 Solutions
CALCULUS+ITS APPL..-MYLAB ACCESS
- EXER 6.3 Find the covariance and the correlation coefficient between X and Y, if X and Y are jointly discrete random variables, with joint PMF given by: SHOW SOLUTIONS X\Y 0 1 6 0 28 6 1 28 2 0 333333 28 28 28 2120 28 0arrow_forwardLet X be a random variable such that E(X²) a. V(3X-3) b. E(3x-3) = 58 and V(X) = 40. Computearrow_forward(Math 161A/163 review) Suppose that X₁, X2, X3 are independent Exponential (A) random variables. A> 0 and r> 0 are constants. Find the mean and variance of Y where Y = 2(X₁+rX2 - X3)arrow_forward
- Part II: Sections 2.1 - 2.7 8. Assume that X is a geometric random variable with p=0.32. (a) Compute P(X > 13[X > 3). (b) Compute E(X²).arrow_forwardIdentify the distributions of the random variables with the moment- generating functions shown below. For each random variable also indicate what the mean and the variance are. a) m(t) = e22(e'–1) b) m(t) = 1/(1 – 2t)² %3D с) т() — 4t d) m(t) = (0.3e + 0.7)18arrow_forwardExercise 3. Let X be a random variable with mean µ and variance o². For a € R, consider the expectation E((X − a)²). a) Write E((X - a)²) in terms of a, μ and σ². b) For which value a is E((X − a)²) minimal? c) For the value a from part (b), what is E((X − a)²)?arrow_forward
- b. Find E[X(X – 1)] for Poisson random variable. Use the result to find the variance of X.arrow_forwardA random variable Y has a uniform distribution over the interval (?1, ?2). Derive the variance of Y. Find E(Y)2 in terms of (?1, ?2). E(Y)2 = Find E(Y2) in terms of (?1, ?2). E(Y2) = Find V(Y) in terms of (?1, ?2). V(Y) =arrow_forwardLet X ∼ U(a, b). Use the definition of the variance of a continuous random variable (Equation 2.38 or 2.39) to show that . σ²X = (b-a)²/12.arrow_forward
- 3. Let X be an exponentially distributed random variable with parameter 2. a) Find and sketch the cdf and pdf of Y = 2- 3X. b) Find the mean and variance of Y. c) Find the distribution of Z = VX. Calculate its mean and variance in Mathematica. d) Obtain characteristic functions of X and Y.arrow_forward1.4 Let X be a continuous random variable with pdf, fx(x), and fx(t+5) = fx(5 – t) for all t> 0. Please provide the mean of X.arrow_forward1. The incidence of cancer among phosphate mine workers and their exposure to radiation was investigated. Cancer incidence was recorded among 60 phosphate mine workers who had 0-29 working level months (WLM) of exposure, 60 phosphate mine workers who had 30-89 WLM of exposure, and 60 phosphate mine workers who had 90-120 WLM of exposure. The number of cancer incidences for each group are presented in Table 1. Table 1: Two-way Table of Counts Cancer Incidence Exposure Level Yes No Total 0-29 WLM 20 40 60 30-89 WLM 33 27 60 90-120 WLM 43 17 60 Total 96 84 180 Perform a x? test, at the 5% level of significance, whether cancer incidence rates differ between the three levels of radiation among phosphate mine workers.arrow_forward
- Calculus: Early TranscendentalsCalculusISBN:9781285741550Author:James StewartPublisher:Cengage LearningThomas' Calculus (14th Edition)CalculusISBN:9780134438986Author:Joel R. Hass, Christopher E. Heil, Maurice D. WeirPublisher:PEARSONCalculus: Early Transcendentals (3rd Edition)CalculusISBN:9780134763644Author:William L. Briggs, Lyle Cochran, Bernard Gillett, Eric SchulzPublisher:PEARSON
- Calculus: Early TranscendentalsCalculusISBN:9781319050740Author:Jon Rogawski, Colin Adams, Robert FranzosaPublisher:W. H. FreemanCalculus: Early Transcendental FunctionsCalculusISBN:9781337552516Author:Ron Larson, Bruce H. EdwardsPublisher:Cengage Learning
![Text book image](https://www.bartleby.com/isbn_cover_images/9781285741550/9781285741550_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9780134438986/9780134438986_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9780134763644/9780134763644_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781319050740/9781319050740_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9780135189405/9780135189405_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781337552516/9781337552516_smallCoverImage.gif)