100 written exams are to be graded, with each exam composed of two questions. Kelvin is in charge of grading question one and Richelle is in charge of grading question two. First, Kelvin grades some exams at random; each exam has probability 0.3 of being graded. Next, Richelle randomly grades half of the exams. That is, she grades 50 exams. Assume Kelvin and Richelle make their choices independently. What is the expected value of the number of exams that Kelvin graded?

100 written exams are to be graded, with each exam composed of two questions. Kelvin is in charge of grading question one and Richelle is in charge of grading question two. First, Kelvin grades some exams at random; each exam has probability 0.3 of being graded. Next, Richelle randomly grades half of the exams. That is, she grades 50 exams. Assume Kelvin and Richelle make their choices independently. What is the expected value of the number of exams that Kelvin graded?

A First Course in Probability (10th Edition)

10th Edition

ISBN:9780134753119

Author:Sheldon Ross

Publisher:Sheldon Ross

Chapter1: Combinatorial Analysis

Section: Chapter Questions

Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...

See similar textbooks

Similar questions

I need help with a and b.
A study tracked a large group of people for 10 years. At the start of the study, 20% were heavy smokers (H), 30% were light smokers (L), and 50% were non-smokers (N). The interest of the study was whether the people in the study died during the study (D) or not die (Dc ). The probability that a light smoker died during the study was twice that of the probability of a non-smoker dying. Also, the probability that light smoker died during the study was half that of the probability of a heavy smoker dying. A randomly selected person from the study died during the study. What is the probability that this person was a heavy smoker (given they died, what is the probability they were a heavy smoker H)?
Please help me answer this. Thank you.
Solve question 3 all parts and show steps for the required parts. Please and thank you.
What is the Probability that none of the houses will be burglarized?
In the basic science unit of the university, the following results were obtained from 350 students: 200 students passed the differential calculus course 160 passed physics course 187 passed probability-statistics course 112 approved differential calculus and probability-statistics 120 passed differential calculus and physics 95 passed physics and probability-statistics 80 passed the three courses. What is the probability of those who passed only one course? a. 0.051 b. 0.1714 c. 0.38 d. 0.0714
In a jury trial, suppose the probability the defendant is convicted given guilt, is 0.95, and the probability the defendant is acquitted given innocence is 0.95. Suppose 90% of defendants are truly guilty. Given that the defendant is convicted, find the probability that he was actually guilty.
If you have a sample of 100 patients at a hospital and 20 of them have the flu, what is the probability Of randomly selecting 3 patients in a row who have the flue?
A certain virus affects 0.7% of the population. A test used to detect the virus in a person is positive 88% of the time if the person has the virus (true positive) and 13% of the time if the person does not have the virus (false positive) Fill out the remainder of the following table and use it to answer the two questions below based on a total sample of 100,000 people. a. Find the probability that a person has the virus given that they have tested positive. Round your answer to the nearest hundredth of a percent and do not include a percent sign. b. Find the probability that a person does not have the virus given that they test negative. Round your answer to the nearest hundredth of a percent and do not include a percent sign.
On any given morning here at Chabot College, coffee is brewed in the Science and Math Division workroom by one of two faculty members, depending on who arrives first at work. Instructor Yest arrives first 75% of the time. Instructor Kelly arrives first the remaining mornings. The probability that the coffee is brewed strong when brewed by Instructor Yest is 0.2. The probability that the coffee is brewed strong when brewed by Instructor Kelly is 0.9, as Instructor Kelly likes her coffee strong! Given the coffee is strong on a randomly selected morning, what is the probability that is was brewed by Instructor Yest?
Jack has just been given a ten-question multiple choice quiz in history class. Each question has five answers, of which only one is correct. Since Jack has not attended class recently, he does not know any of the answers. Assuming Jack guesses randomly on all ten questions, find the probability that he will answer six or more of the questions correctly and avoid an F.
On the average the traffic pattern at an intersection is as follows: • Twice as many cars go through as the number of vans, bicycles and trucks combined. • Twice as many vans go through as the number of bicycles and trucks combined. • Half as many trucks go through as the number of bicycles. Calculate the probability that the next vehicle to go through is a truck or a car. (19/27)