Explore BrainMass


Desired failure rate, reliability analysis, confidence levels

A "one-shot" device can be used only once; after use, the device (e.g. a nuclear weapon, space shuttle, automobile air bag) either is destroyed or must be rebuilt. The destructive nature of a one-shot device makes repeated testing either impractical or too costly. Hence, the reliability of such a device must be determined with m

Study of population concentrations in urban counties by Nevada commissioners

Researchers at the University of Nevada at Reno asked a sample of county commissioners to give their perception of the single most important factor in identifying study of urban countries (Professional Geographer, Feb. 2000.) In all, five factors were mentioned by the commissioners; total population, agricultural change, presenc

Probablity that buyer will have two healthy trees with no Dutch Elm disease.

A nursery advertises that it has 10 elm trees for sale. Unknown to the nursery, 3 of the trees have already been infected with Dutch Elm disease and will die within a year. a- If a buyer purchases two trees, what is the probability that both trees will be healthy? b- Refer to part a. what is the probability that at least

Hospital Emergency room new patients: Probability of not enough beds

The mean number of the patients admitted per day to the emergency room of a small hospital is 2.5. If, on a given day, there are only four beds available for new patients, what is the probability that the hospital will not have enough beds to accommodate its newly admitted patients?

Binomial Probability: Number of Accident Claims

Accident claims are checked for completeness by branch offices of Fortune Insurance before they are sent to a regional office for payment. Historically 80% of the claimes are complete whenthey reach the regional office. You select a random sample of 20 claimes that have arrived at the regional office. Find the probability of

Probabilities about House Sales: Number of Days to Sell

5. A nationwide real estate company claims that its average time to sell a home is 57 days. Suppose it is known that the standard deviation of selling times is 12.3 days and that selling times are normally distributed. a. Assuming the company's claim is true, if one home is selected at random, what is the probability that it

Binomial Probability: Women truck drivers

1. Five percent of American truck drivers are women. Suppose 10 truck drivers are selected randomly to be interviewed about quality of work conditions. A) Is the selection of the 10 drivers a binomial experiment? Explain the reasons for your answer. B) What is the probability that two of the drivers will be women? C) What

Martin Manufacturing: Probability of defects in a sample

Martin Manufacturing produces cases for personal computers and other electronic equipment. The quality control inspection procedure is to select 6 items, and if there are 0 or 1 defective cases in the group of 6, the process is said to be in control. If the number of defects is more than 1, the process is out of control. Suppose

Model to optimize number of possible bids given budgets

The attached files provide a definition of the problem, especially the powerpoint slide. Given the information, I am trying to develop a linear programming model such that I maximize the number of possible bids given the limited resources of budgets and writers. Essentially, which of the 10 bids should I take on, given the

6 Statistics Problems: Identify Probability Distributions

Identify Probability Distributions Determine whether or not a probability distribution is given. If a probability distribution is given, find its mean and standard deviation. If a probability disbribution is not given, identify the requiremtns that are not satisfied. 10. Eye Color Groups of five babies are randomly sele

Discrete Probability Distribution: game show for big money prizes

Discrete Probability Distribution ??? Imagine you are in a game show, where there are big money prizes that can be won. Now, let us start the money give-away! There are 4 prizes hidden on a game board with 16 spaces. One prize is worth $4000, another is worth $1500, and two are worth $1000. But, wait!!! You are also

Carbon Monoxide (CO) poisoning sampling experiment

See attached file for the table. Carbon monoxide (CO) is a colorless, odorless, tasteless toxic gas produced by incomplete combustion in fuel-burning devices. Persons with CO poisoning often overlook the symptoms. In Ontario, a total of 981 cases of unintentional CO poisoning was reported. Each case was classified as fata

Statistics: Z score, normal distribution, SAT scores, people selected for juries

See attached file. 1. For a population with a mean of µ=60 and a standard deviation of ?=24, find the z-score corresponding to each of the following samples. A. M=63 for a sample of n=16 scores B. M=63 for a sample of n=36 scores C. M=63 for a sample of n=64 scores 2. A population of scores forms a normal distribution


1. How many ways can an EMT union committee of 5 be chosen from 25 EMTs? 100 125 15,504 53,130 2. Which of the following cannot be a probability? 0 -49 0.001 14% 3. List the sample space of rolling a 6 sided die. {1, 3, 5}

Statistics: Absences of blue-collar workers

4. In an article in the Journal of Management, Joseph Martocchio studied and estimated the costs of employee absences. Based on a sample of 176 blue-collar workers, Martocchio estimated that the mean amount of paid time lost during a three-month period was 1.4 days per employee with a standard deviation of 1.3 days. Martocchio a

Calculate conditional probabilities

• "29% of men admitted they had cheated" means that total at the bottom of the column labeled 'Male cheating' becomes .29 x 203 = 59 • "compared with 18.5% of women" implies this percent of females had cheated, or the total in the 'Female cheating' column is .185 x 203 = 38 Female cheating Female not cheating Total Ma

Probability of Samples Containing Female Students

In a large university, 15% of the students are female. If a random sample of twenty students is selected, a. what is the probability that the sample contains exactly four female students? b. what is the probability that the sample will contain no female students? c. what is the probability that the sample will contain

Statistics: Sun Love grapefruit production. How many were harvested this year?

Sun Love grapefruit growers have determined that the diameters of their grapefruits are normally distrubuted with a mean of 4.5 inches and a standard deviation of 0.3 inches. A) What is the probability that a randomly selected grapefruit will have a diameter of at least 4.14 inches? B) What percentage of the grapefruits has

Statistics: continuous probability distribution

I need some help with the following statistical concepts: Now we are going to talk about continuous probability distributions. In a continuous probability distribution, the variable can have a value within a range. The most common continuous distribution is the standard normal distribution, select a continuous random varia