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Fifty percent of Americans believed the country was in a recession, even though technically had not shown two straight quarters of negative growth (Business Week, July 30, 2001). For a sample of 20 Americans, make the following calculations. a. Determine the probability that exactly 12 people believed the country was in a re

Probability problem

3. A production line manufactures 1000 ohms resistors that must satisfy a 10% tolerance. a. If a resistance is adequately described by a Gaussian random variable for which mean = 1000; and standard deviation = 40;, what fraction of the resistance expected to be rejected? b. If a machine is not properly adjusted, the produc


In an article about investment growth, Money magazine reported that drug stocks show powerful long-term trends and offer investors unparalleled potential for strong and steady gains. The federal Health Care Financing Administration supports this conclusion through its forecast that annual prescription drug expenditures will reac

Quantitative Methods

Hello Brainmass: Please answer the attached 60 Quantitative methods questions (some are t or f, some are multiple choice). This would be a great study guide for me.


The U.S. Bureau of Labor Statistics collected data on the occupations of workers 25 to 64 years old. The following table shows the number of male and female workers (in millions) in each occupation category (Statistical Abstract of the United States: 2002) (see chart in the attached file) a. Develop a joint probability tab

Binomial Distributions and Z-Scores

1. A door to door salesperson believes that the probability of making a sale when a person is at home is 0.4 he visits 10 homes. When someone is at home find the probability of making a) exactly 7 sales b) more than 7 sales 2.For a binomial distribution with an n=200 and p=0.3 calculate the probability of obtaining between 50

Probability Theory

Indicate whether the sentence or statement is true or false. T 1. Deterministic techniques assume that no uncertainty exists in model parameters. F 2. The probabilities of mutually exclusive events sum to zero. T 3. A joint probability is the probability that two or more events that are not mutually exclusiv

Joint Probability

F(x,y) = kxy over triangular region 0 < y <2X and 0 < x <3 I need to find K which I typical know how to do, set the double integeral of both the X and Y limits of the function equal to one and solve for K. However in this problem what do I do with 2X in my upper y limit, can I plug in the max x value and just make it 0 < y

Joint and Marginal Probability Distributions

Person takes bus & subway to work. Bus runs every 20 min (X) & subway every 4 min (Y). Assume timing of the bus and subway are independet and uniform. ------------------ I need to find the joint and marginal distribtions for this problem. Since they are independent I know that f(x,y) = fx(x) * fy(y) but do not understand how

Simple Probability, Sample Spaces, Events

A couple has three children, assume the likelihood of a boy is the same as a girl: List sample space: {BBB,BBG,BGG,GGG} Event the children are grils: {GGG} Event the couple has one or more boy: {BBB,BBG,BGG} Probability all children are girls: 1/4 Probability the couple has at least one boy: 3/4 Probability the couple ha

Probability; Eliminate the paramter to find a cartesian equation of the curve; Sketch the curve and indicate with an arrow the direction in which the curve is traced as the parameter increases

1) The manager of a fast food restaurant determines that the average time that her customers wait for service is 2.5 minutes. a) Find the probability that a customer has to wait for more than 4 mintues. b) Find the probability that a customer is served within the first 2 minutes. Now, this was all worked out, but some ste

Probability & Statistics : Mean, Median and Histograms

9. The price-to-earnings (PE) ratio of a stock is the ratio of a stock's most recent price per share to the stock's earnings per share (averaged over a 12-month period). Listed below are the PE ratios for 40 randomly selected securities traded on the New York Stock Exchange (NYSE) on Wednesday, August 24, 2005. Stock PE R

Combinations and Subsets : Probabilities

A committee consists of 8 married couples. In how many ways can a subcommitee of 5 people be chosen so that at most one married couple belongs to the subcommittee?

Process Flow Time - Queueing Problem and Critical Assumptions

Fort Lost-in-the-Woods is a basic training center for new Army recruits. Upon arriving at the military post the new recruits are processed through the Induction Center that involves three steps: background information gathering, medical examination, and barracks assignment. Arriving inductees first enter the Center's Background

Frequency Table

A secretary periodically checks to see how mnay of the three lines into the office are busy. Her findings for one week were the following: No. Lines busy Frequency 0 20 1 65 2 25 3

Probability : Independent Dual Probability

A student applies for two different scholarships. The probability of receiving the first scholarship is 0.3 and the probability of receiving the second is 0.4. The decisions are made independently. Find the probability the student receives exactly one scholarship. A. 0.12 B. 0.42 C. 0.46 D. 0.40

Probability and Standard Deviation

A Recent survey indicates that the average salary of all entry-level women managers in St. Paul is $56,700 with a standard deviation $7,200. What is the probability that a random sample of 50 such women will yield a mean entry-level that exceeds $58,000?

Probability problem

The single shot probability of kill of any weapon system (gun, missle or slingshot) is less than 1 due to the reliability factors if no other reason. Suppose the single shot probability of kill of a new defensive missle system is 0.75%, and the the probability is not considered adequate. One familiar strategy to increase the o

Probability : The ELISA test was introduced in the mid-1980s to screen blood for the presence of AIDS antibodies. When antibodies are present ELISA is positive 98% of the time; when the blood lacks..

The ELISA test was introduced in the mid-1980s to screen blood for the presence of AIDS antibodies. When antibodies are present ELISA is positive 98% of the time; when the blood lacks the antibidies the ELISA is positive 7% of the time. Assuming that 1% of the population has AIDS antibodiesin their blood, what is the probabili

Probability : Expected Values and Probability Distributions - According to an automobile manufacturer, the company uses 3,000 lock-and-key combinations on it's vehicles. Suppose that you find a key..

According to an automobile manufacturer, the company uses 3,000 lock-and-key combinations on it's vehicles. Suppose that you find a key for one of those cars. a) What is the expected number of vehicles that you would have to check to find one that fits your key? b) What is the probability that you would have to check