Explore BrainMass


A project using PERT

A project was planned using PERT with three times estimates. The expected completion time of the project was determined to br 40 weeks. The variance of the critical path is 9. A What is the probability that the project will be finished in 40 weeks or less? B. What is the probability that the project takes longer than 40 we


1. Discuss the concepts of random variable and a probability distribution. 2. A university found that 20% of its students withdraw without completing the introductory statistics course. Assume that 20 students registered for the course. a. Compute the probability that 2 or fewer will withdraw b. Compute the

Computing Binomial Probability Distribution

Assume a binomial probability distribution with n=40 and Ï? =.30(pi =.30). (Round all z values to 2 decimal places.) Compute the following: (a) The mean and standard deviation of the random variable. (Round your "Ï?" to 4 decimal places and mean to 1 decimal place) ?= ?= (b) The probability that X is 16

Queuing Analysis Problem

The Riverview Clinic has two general practitioners who see patients daily. An average of six patients arrive at the clinic per hour. Each doctor spends an average of 15 minutes with a patient. The patients wait in a waiting area until one of the two doctors is able to see them. However, because patients typically do not feel

Queuing Analysis ..

The Bay City Police Department has eight patrol cars that are on constant call 24 hours a day. A patrol car requires repairs every 20 days, on average, according to an exponential distribution. When a patrol car is in need of repair, it is driven into the motor pool, which has a repair person on duty at all times. The average

Decision Analysis

Use the data in the following payoff matrix and regret matrix to answer the following questions: Payoff Matrix Airport is Built at Location Land Purchased at Location(s) A B A $75.0 $15.0 B ($25.0) $125.0 A&B

Practice set

16. Assume that two marbles are drawn without replacement from a box with 1 blue, 3 white, 2 green, and 2 red marbles. Find the probability of the indicated result. The second marble is blue, given that the first marble is blue. a. 1/28 b. 0 c. 1/7 d. 1/8 17. Find the probability. In a certain city,


Among U.S. cities with a population of more than 250,000 the mean one-way commute to work is 24.3 minutes. The longest one-way travel time is New York City, where the mean time is 37.9 minutes. Assume the distribution of travel times in New York City follows the normal probability distribution and the standard deviation is 6.9 m


According to a government study among adults in the 25- to 34-year age group, the mean amount spent per year on reading and entertainment is $2,020. Assume that the distribution of the amounts spent follows the normal distribution with a standard deviation of $456. (Round z-score computation to 2 decimal places and your final an

Step by step probability problems

Please send detailed solutions in 2 hours. 1. You have grown soybeans for 40 years, and have experienced 5 crop failures in that time period. What is the probability of a crop failure in any given year? 2. Based on the annual probability of crop failure you found in question 1, what is the expected number of crop failures

Probability and demand for ABC company

2. The demand for a product of ABC company varies greatly from month to month. The probability distribution of the company's monthly demand is given in the following table Demand (in units) Probability 300 0.20 400 0.30 500 0.35 600 0.15 (a) If the company orders the expected monthly demand amount, what should ABC's mon

book review probability of random selection

2. The editor of a publishing company is trying to decide whether to publish a proposed business statistics textbook. Information on previous textbooks published indicates that 10% are huge successes, 20% are modest successes, 40% break-even, and 30% are losers. However, before publishing decision is made, the book will be revie

Probability Review Questions

Question 1 The following five (5) situations require the application of one of the common discrete or common continuous distributions we learned about. All you have to do for each of these problems is identify the correct probability mass function or probability density function name. DO NOT SOLVE THE PROBLEM. There is only

Queuing and Process Simulation Modeling

Michael's Tire Company performs free tire balance and rotation for the life of any tires purchased there on a first-come, first-served basis. One mechanic handles this and can usually complete the job in an average of 20 minutes. Customers arrive at an average rate of two per hour for this service. a. How long will a customer

Queues and process simulation modeling

1. Star Savings and Loan is planning to install a drive-through window. Transaction times at the drive-through are expected to average three minutes because customers would use it for simpler transactions. The arrival rate is expected to be ten customers per hour. a. Compute the operating characteristics for the drive-through w

What is the probability?

1. A group of volleyball players consists of four Grade-11 students and six Grade-12 students. If six players are chosen at random to start a match, what is the probability that three will be from each grade? 2. If a bowl contains ten hazelnuts and eight almonds, what is the probability that four nuts randomly selected from t

Probability Distributions

1. Suppose you randomly draw two marbles, without replacement from a bag, containing six green, four red and three black marbles. a) Determine the probability that both marbles are red. b) Determine the probability that you pick at least one green marble. 2. What is the probability of at least two people in a class o

Probability of Rolling the Given Sum on Two Dice

You are rolling a pair of dice, one red and one green. What is the probability of the following out comes: a. The sum of the two numbers you roll from the dice is 8. b. The sum of the two numbers you roll is 12. c. The sum of the two numbers you roll is 7.

Introduction to Probability Review

Two coins are tossed simultaneously. What is the probability of tossing two heads? A coin is tossed three times. What is the probability of tossing exactly two heads? Two standard dice are rolled. What is the probability of rolling a total of 9? If the odds in favour of rain tomorrow are 4:7, what is the probability of

Probability Measurements

1 ) The following are measurements of the diameter of engine crankshafts in millimeters. The process mean is supposed to be 224. What is the probability that a similar study would have the same sample mean or higher? 224.120 224.001 224.017 223.989 223.960 223.961 224.089 2) Cola drink makers try to keep the sweetness of

Empirical and Theoretical probability

1)How well we understand the difference between empirical and theoretical probability is an important part of our ability to apply probability to a real world set of data. What is the difference between empirical and theoretical probability? Give two to three examples of professions where probability could be used. Explain your


3. At a certain university, 30% of the students major in mathematics. Of the students majoring in mathematics, 60% are males. Of all the students at the university, 70% are males. a. What is the probability that a student selected at random in the university is male and majors in mathematics? b. What is the probability that a

Probability: Bay's Theorem..

4. Seventy percent of all Big Burger chain stores decided to advertise in their local newspapers. Of those chain stores that advertised in their local newspapers, 60% had an increase in sales. Of those chain stores that did not advertise in their local newspapers, 25% had an increase in sales. a. What is the probability that

Marginal & Conditional Probability for Marketing Survey

2. For a marketing survey, 200 customers were classified according to their age (in years) and their favorite type of donut. Age of Customer Glazed Chocolate-covered Crème-filled Cake <21 3 25 10 7 21-30 5 23 26 10 31-45 15 12 3 20 >45 29 5 1 6 (a) What is the probability that a person prefers Creme-filled donut and is a

subjective probability

1. Match each of these terms with one of the phrases below. Terms: a. sample space b. events c. complement d. subjective probability e. outcomes f. theoretical probability g. trials Phrases: 1. deduced from analysis of all possible outcomes 2. the set of all possible outcomes 3. repetitions of a probability experimen

Probability 2: Qualitative Data of 10 Observations

Your specific assignment for this week is to select a type of quantitative data to collect from your own life. Some examples of data to collect could be: How long it takes to drive to work each day. How many hours of TV shows you watch each day. Number of phone calls you get each day. In a brief paper, describe the


Solve the following problems showing your work: 1. Suppose you have 4 nickels, 6 dimes, and 4 quarters in your pocket. If you draw a coin randomly from your pocket, what is the probability that a. You will draw a dime? b. You will draw a nickel? c. You will draw a quarter? 2. You are rolling a pair of d

Expected Value Problem

There are 7 prisoners, and 7 rooms each with a switch. Assume all switch are off at first. Now there is a fair coin in each room. Each prisoner goes to each room and flips the coin. If the coin comes up heads, prisoner changes the state of the switch. Else, prisoner moves to the next room and repeats. What is the average numb