
A First Course in Probability (10th Edition)
10th Edition
ISBN: 9780134753119
Author: Sheldon Ross
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Question

Transcribed Image Text:6. We have three light bulbs with lifetimes \( T_1, T_2, T_3 \) distributed according to Exponential(\(\lambda_1\)), Exponential(\(\lambda_2\)), Exponential(\(\lambda_3\)). In other words, for example bulb #1 will break at a random time \( T_1 \), where the distribution of this time \( T_1 \) is Exponential(\(\lambda_1\)). The three bulbs break independently of each other.
The three light bulbs are arranged in series, one after the other, along a circuit—this means that as soon as one or more light bulbs fail, the circuit will break. Let \( T \) be the lifetime of the circuit—that is, the time until the circuit breaks.
---
**(a)** What is the CDF of \( T \), the lifetime of the circuit?
**(b)** Next, suppose that we only check on the circuit once every second (assume the times \( T_1, T_2, T_3, T \) are measured in seconds). Let \( S \) be the first time we check the circuit and see that it’s broken. For example, if the circuit breaks after 3.55 seconds, we will only observe this when 4 seconds have passed, and so \( S = 4 \). Calculate the PMF of \( S \).
**(c)** Finally, suppose that instead of checking on the circuit every second, we instead do the following: after each second, we randomly decide whether to check on the circuit or not. With probability \( p \) we check, and with probability \( 1 - p \) we do not check. This decision is made independently at each time. Now let \( N \) be the number of times we check and see the circuit working. For example, if the circuit breaks at time 3.55, and our choices were to check at time 1 second, not to check at times 2 or 3 or 4, and to check at time 5, then \( N = 1 \), since the circuit was broken the 2nd time we checked.
What is the PMF of \( N \)? (Hint: start by finding the joint PMF of \( N \) and \( S \). It's fine if your answer is in summation form.)
Expert Solution

This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
This is a popular solution
Trending nowThis is a popular solution!
Step by stepSolved in 2 steps with 17 images

Knowledge Booster
Similar questions
- A doctor prescribes 100 milligrams of a therapeutic drug that decays by about 20% eachhour (ie. after 1 hour, 20% of the drug is gone). Assume the quantity of the drug is modeled by anexponential equation. What is the half-life of the drug? Please use a calculator to compute the finalanswer and round down to two decimal places.arrow_forwardDetermine whether the following scenarios are linear or exponential. As summer approaches, I noticed that for every increase in 5 degrees, the number of people I see at the pool increases by about 3. The amount of Francium,a radioactive element, decays by about 3.1% every minute. The number of flu cases increases by about 1.6% per month during flu season. Based on Mrs. Olivet's Test 4 results, students tended to score about 4 more points on their test for every hour they studied. The percentage of the population that has been vaccinated for COVID-19 increased by about 0.25 percentage points every day in January. The population of bugs in Monica's walls decreased by 80% every week while the exterminator was treating her home. During a rainstorm the reading from the rain gauge increased by a quarter inch every hour. Selene didn't want her parents to notice she was stealing candy from the jar, so every day she only ate 1/8 of what was left. While writing an essay, Carson writes 7…arrow_forwardA app.edulastic.com lever | Teacher.. Launch Meeting -. C Classes A 8 Advisory Michi. O Launch Meeting. E Edulastic: Format. Question 20/26 > NEXT A BOOKMARK A population of bacteria, B , can be modeled using the exponential function B (x) = 3 (2)" , where a is the number of days since th population was first observed. Which domain is most appropriate to use to determine the population over the course of the first weel- A00 15 tv MacBook Air 80 888 DII DD F1 F3 F4 F5 F6 F7 FB @ $ % & 1 2 3 4 8 Q W E R T Y S Karrow_forward
- A Northwest Airlines ticket counter forecasts that 40 people per hour will need to check in. It takes an average of 1.2 minutes to services a customer. Assume that interarrival times and service times are exponential and that all customers wait in a single line for the first avaliable agent. If we want the average time a customer spends in line and in service to be 4 minutes or less, how many ticket agents should be on duty?arrow_forwardModel the following data using an exponential function of the form f(x) = Ab". You need to do this rigorously, that is, set up a system of equations, and solve it to get A and b. Getting the right answer by guessing will earn no credit. (a) f(x) is exponential and goes through the points (1, 2) and (4,6). (b) f(x) is exponential and goes through the points (2, 75) and (5, 9375).arrow_forwardImagine that COVID-19 had spread exponentially in Maine since the first case (on March 12). Using the model f(t)=A02t/d with A0=1 and t= number of days since March 12, find D with the knowledge that there were 7,603 total cases on Nov. 7, 240 days after March 12.arrow_forward
- Using two six-sided dice, what is the probability of rolling two doubles in a row? There are six possible doubles, 1 & 1 through 6 & 6, out of 36 possible rolls. Multiply for a series of events. Remember to reduce. Probability of 2 doubles is Ratio: ___ : __arrow_forwardHow am i supposed to solve these tables without the given function? (#5)arrow_forward8. Which exponential equation matches the graph shown? (1,6) (0,2) a. c. b. y- 2(3)* d. y-2(3)"arrow_forward
arrow_back_ios
arrow_forward_ios
Recommended textbooks for you
- A First Course in Probability (10th Edition)ProbabilityISBN:9780134753119Author:Sheldon RossPublisher:PEARSON

A First Course in Probability (10th Edition)
Probability
ISBN:9780134753119
Author:Sheldon Ross
Publisher:PEARSON
