hw.pdf

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All work to be shown. Partial Credit is possible. (Must show detailed steps to get full credit) 1. Find the cumulative distribution function and instantaneous hazard rate function for the following three cases: (10 Points) a. Case 1: PDF: f(t) = λ*e -λt where t >=0 and λ >=0 b. Case 2: PDF: f(t) = (2/n) * t* e [(-t^2)/n] where t >=0 and n >=0 2. The weight, X, of a metal ingot produced in a casting foundry follows normal distribution. The mean and standard deviation of X are μ = 520 pounds and σ = 11 pounds respectively. Find the following: (10 points) a. P(X<=525) b. P(509<=X<=531) c. Central 98% probability of limits of ingot weights d. P(μ +/- 1σ), P(µ +/- 2σ) and P(µ +/- 3σ) 3. The experimental data obtained with a set of 10,000 identical components is shown below. Find the corresponding failure rate versus time and plot the curve (15 points). What is your best estimation of the failure rates in three regions of the graph? (15 points). Assuming hazard rate values you calculated, what are the probability density functions of three regions? (10 points) Time of observation (hours) Number of components operating at time, t 0 10,000 50 8880 100 8300 150 7918 200 7585 250 7274 300 6968 350 6668 400 6375 450 6088 500 5808 550 5535 600 5269 650 5011 700 4760 750 4517 800 4237 850 3864 900 3396 950 2819 1000 2219

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  • All work to be shown. Partial Credit is possible.

    (Must show detailed steps to get full credit)

    1. Find the cumulative distribution function and instantaneous hazard rate function for the following three cases: (10 Points)

    a. Case 1: PDF: f(t) = *e-t where t >=0 and >=0 b. Case 2: PDF: f(t) = (2/n) * t* e[(-t^2)/n] where t >=0 and n >=0

    2. The weight, X, of a metal ingot produced in a casting foundry follows normal distribution. The mean and standard deviation of X are = 520 pounds and = 11 pounds respectively. Find the following: (10 points)

    a. P(X

  • 4. A local manufacturer of toaster includes a repair warranty with the product. The toaster exhibits an exponential increasing failure rate, approximated by the function: r(t) = 2.8 t1.4, where t is measured in years of continuous operation. What is the probability that the time between two successive failures exceeds three months of operation? (20)

    5. The reliability of a forging press is given by

    R(t) = (1-t/Tmax)^3 for 0